Docetaxel/anthracycline combinations for breast cancer treatment

Enhanced chemotherapeutic efficacy of docetaxel in human lung cancer cell line via GLUT1 inhibitor

The dose-dependent adverse effects of anticancer agents need new methods with lesser toxicity. The objective of the current research was to evaluate the efficacy of GLUT1 inhibitor, as an inhibitor of glucose consumption in cancer cells, in augmenting the efficiency of docetaxel with respect to cytotoxicity and apoptosis. Cell cytotoxicity was assessed by using methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. Annexin V/PI double staining was employed to evaluate apoptosis percentage. Quantitative real-time polymerase chain reaction (RT-PCR) analysis was accomplished to detect the expression of genes involved in the apoptosis pathway. The IC50 values for docetaxel and BAY-876 were 3.7 ± 0.81 and 34.1 ± 3.4 nM, respectively. The severity of synergistic mutual effects of these agents on each other was calculated by synergy finder application. It showed that the percentage of apoptotic cells following co-administration of docetaxel and BAY-876 increased to 48.1 ± 2.8%. In comparison without GLUT1 co-administration, the combined therapy decreased significantly the transcriptome levels of the Bcl-2 and Ki-67 and a remarkable increase in the level of the Bax as proapoptotic protein(p < 0.05). Co-treatment of BAY-876 and docetaxel depicted a synergistic effect which was calculated using the synergy finder highest single agent (HSA) method (HSA synergy score: 28.055). These findings recommend that the combination of GLUT-1 inhibitor and docetaxel can be considered as a promising therapeutic approach for the treatment of patients with lung cancer.

Transcriptome analysis of long noncoding RNAs reveals their potential roles in anthracycline-induced cardiotoxicity

Aims

Anthracyclines (ANTs) are essential chemotherapeutic agents; however, their adverse effects can lead to heart failure in cancer survivors. While long non-coding RNAs (lncRNAs) have become new players in cellular processes, there is limited knowledge on lncRNA expression related to anthracyclines-induced cardiotoxicity. This study investigates the lncRNA profiles in human cardiac microtissues exposed to 3 popular ANTs, namely doxorubicin, epirubicin, and idarubicin, as well as in heart biopsies from ANT-treated patients.

Methods and results

The in vitro microtissues were exposed to each ANT at 2 doses over 2 weeks; the transcriptome data was collected at 7 time points. The human biopsies were collected from heart failure patients who underwent ANT treatment and control subjects. Over 100 lncRNAs were differentially expressed in each in vitro ANT treatment condition compared to control samples; 16 of them were differentially expressed across all ANT-treated conditions. The lncRNA databases and literature revealed insight on how these lncRNAs relate to heart failure and cellular functions. For instance, H19 and RMRP are involved in heart failure progression, while BDNF-AS is a cardiomyocyte damage-associated gene; SNHG7 is a cardiac hypertrophy regulator. PCAT19 can promote the miR‐182/PDK4 axis and modulate p53 expression, whereas SNHG29 can regulate the Wnt/β-catenin signaling pathway via the miR-223–3p/CTNND1 axis. Other lncRNAs, which were only differentially expressed in particular ANT-treated conditions, are also involved in cardiomyocyte damage and heart failure disease. The alterations of these lncRNA expressions in the in vitro cardiac tissue were also affirmed by similar changes in the human biopsies.

Conclusion

This study revealed several lncRNAs that can be potential biomarkers or targets for further ANT-induced cardiotoxicity investigation, according to the transcriptome in both human cardiac microtissues expose to ANTs as well as in heart biopies form ANT-treated patients. Especially, H19 lncRNA showed its contribution to on-target toxicity, in which it is involved in both chemoresistance and cardiotoxic mechanism.

Comparison of Autologous Breast Reconstruction Complications by Type of Neoadjuvant Chemotherapy Regimen

BACKGROUND

Neoadjuvant chemotherapy before mastectomy helps reduce tumor burden and pathologic response in breast cancer. Limited evidence exists regarding how neoadjuvant chemotherapy impacts outcomes following microvascular breast reconstruction. This study examines the effects of neoadjuvant chemotherapy regimens and schedules on microvascular breast reconstruction complication rates and also assesses the effects of neoadjuvant chemotherapy on circulating immune cells related to wound healing.

METHODS

Patients who underwent neoadjuvant chemotherapy and microvascular breast reconstruction at Yale New Haven Hospital between 2013 and 2018 were identified. Demographic variables, oncologic history, chemotherapy regimens, and complication profiles were collected. Chemotherapy regimens were stratified by inclusion of anthracycline and order of taxane administration. Chi-square, Fisher's exact, and t tests were used for univariate analysis. Multivariate binary logistic regression was used to control for covariates.

RESULTS

One hundred patients met inclusion criteria. On multivariate analysis, the administration of taxane first in an anthracycline-containing chemotherapy sequence was associated with increased complications (OR, 3.521; p = 0.012), particularly fat necrosis (OR, 2.481; p = 0.040). In the logistic regression model evaluating the effect of the taxane-first regimen on complication rates, the area under the curve was estimated to be 0.760 (p < 0.0001), particularly fat necrosis 0.635 (p < 0.05). The dosage of chemotherapy, number of days between neoadjuvant chemotherapy completion and surgery, and number of circulating immune cells did not significantly differ among patients who experienced complications.

CONCLUSIONS

Taxane-first, anthracycline-containing neoadjuvant chemotherapy regimens were associated with increased complications, particularly fat necrosis. The increased postreconstruction complication risk must be weighed against the benefits of taxane-first regimens in improving tumor outcome.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Translational Proteomics Analysis of Anthracycline-Induced Cardiotoxicity From Cardiac Microtissues to Human Heart Biopsies

Anthracyclines, including doxorubicin, idarubicin, and epirubicin, are common antitumor drugs as well as well-known cardiotoxic agents. This study analyzed the proteomics alteration in cardiac tissues caused by these 3 anthracyclines analogs. The in vitro human cardiac microtissues were exposed to drugs in 2 weeks; the proteomic data were measured at 7 time points. The heart biopsy data were collected from heart failure patients, in which some patients underwent anthracycline treatment. The anthracyclines-affected proteins were separately identified in the in vitro and in vivo dataset using the WGCNA method. These proteins engage in different cellular pathways including translation, metabolism, mitochondrial function, muscle contraction, and signaling pathways. From proteins detected in 2 datasets, a protein-protein network was established with 4 hub proteins, and 7 weighted proteins from both cardiac microtissue and human biopsies data. These 11 proteins, which involve in mitochondrial functions and the NF-κB signaling pathway, could provide insights into the anthracycline toxic mechanism. Some of them, such as HSPA5, BAG3, and SH3BGRL, are cardiac therapy targets or cardiotoxicity biomarkers. Other proteins, such as ATP5F1B and EEF1D, showed similar responses in both the in vitro and in vivo data. This suggests that the in vitro outcomes could link to clinical phenomena in proteomic analysis.

Orally effective FDA-approved protein kinase targeted covalent inhibitors (TCIs)

Because dysregulation of protein kinases owing to mutations or overexpression plays causal roles in human diseases, this family of enzymes has become one of the most important drug targets of the 21st century. Of the 62 protein kinases inhibitors that are approved by the FDA, seven of them form irreversible covalent adducts with their target enzymes. The clinical success of ibrutinib, an inhibitor of Bruton tyrosine kinase, in the treatment of mantle cell lymphomas following its approval in 2013 helped to overcome a general bias against the development of irreversible drug inhibitors. The other approved covalent drugs include acalabrutinib and zanubrutinib, which also inhibit Bruton tyrosine kinase. Furthermore afatinib, dacomitinib, and osimertinib, inhibitors of members of the epidermal growth factor receptor family (ErbB1/2/3/4), are used in the treatment of non-small cell lung cancers. Neratinib is an inhibitor of ErbB2 and is used in the treatment of ErbB2/HER2-positive breast cancer. The seven drugs considered in this review have a common mechanism of action; this process involves the addition of a protein cysteine thiolate anion (protein‒S:^-) to an acrylamide derivative (CH₂=CHC(=O)N(H)R) where R represents the pharmacophore. Such reactions are commonly referred to as Michael additions and each reaction results in the formation of a covalent bond between carbon and sulfur; the final product is a thioether. This process consists of two discrete steps; the first step involves the reversible association of the drug with its target enzyme so that a weakly electrophilic functionality, a warhead, is bound near an appropriately positioned nucleophilic cysteine. In the second step, a reaction occurs between the warhead and the target enzyme cysteine to form a covalently modified and inactive protein. For this process to work, the warhead must be appropriately juxtaposed in relationship to the cysteinyl thiolate so that the covalent addition can occur. Covalent inhibitors have emerged from the ranks of drugs to be avoided to become an emerging paradigm. Much of this recent success can be attributed to the clinical efficacy of ibrutinib as well as the other antagonists covered in this review. Moreover, the covalent inhibitor methodology is swiftly gaining acceptance as a valuable component of the medicinal chemist's toolbox and is primed to make a significant impact on the development of enzyme antagonists and receptor modulators.

Regimens of neo-adjuvant chemotherapy in the treatment of breast cancer: A systematic review & network meta-analysis with PRISMA-NMA compliance

Efficacy of neo-adjuvant therapy depends on the used regimens. There are contradictory findings regarding relative efficacy of these regimens. Accordingly, present study assessed the relative efficacy of Anthracyclines, Taxanes and added targeted therapies in neo-adjuvant setting simultaneously with a focus on tumor response and breast conserving surgery among breast cancer patients. The network meta-analysis model was used. Ranking of treatment was done by surface under cumulative ranking curve for each regimen. Out of 1286 screened records obtained by searching PubMed and Cochrane register of controlled trials, a total of 34 studies randomizing 12,630 breast cancer patients were included. Network meta-analysis for pathological complete response (pCR) revealed Addition of targeted therapies especially Trastuzumab for HER2+ breast cancer and Bevacizumab for HER2- breast cancer along with Anthracyclines and/or Taxanes based chemotherapy significantly improves pCR but with increased haematological toxicities. All the regimens performed similar in terms of breast conserving surgery rates.

KSP siRNA/paclitaxel-loaded PEGylated cationic liposomes for overcoming resistance to KSP inhibitors: Synergistic antitumor effects in drug-resistant ovarian cancer

Despite the promising anticancer effects of kinesin spindle protein (KSP) inhibition, functional plasticity of kinesins induced resistance against KSP inhibitors in a variety of cancers, leading to clinical failure. Additionally, paclitaxel is a widely used anticancer agent, but drug resistance has limited its use in the recurrent cancers. To overcome resistance against KSP inhibitors, we paired KSP inhibition with microtubule stabilization using KSP siRNA and paclitaxel. To enable temporal co-localization of both drugs in tumor cells in vivo, we exploited PEGylated cationic liposomes carrying both simultaneously. Drug synergism study shows that resistance against KSP inhibition can be suppressed by the action of microtubule-stabilizing paclitaxel, because microtubule stabilization prevents a different kinesin Kif15 from replacing all essential functions of KSP when KSP is inhibited. Our combination therapy showed more effective antiproliferative activity in vitro and in vivo than either paclitaxel or KSP siRNA alone. Ultimately, we could observe significantly improved therapeutic effects in the drug-resistant in vivo models, including cell line and patient-derived xenografts. Taken together, our combination therapy provides a potential anticancer strategy to overcome resistance against KSP inhibitors. Particularly, this strategy also provides an efficient approach to improve the therapeutic effects of paclitaxel in the drug-resistant cancers.

miR-221/222 activate the Wnt/β-catenin signaling to promote triple-negative breast cancer

Triple-negative breast cancer (TNBC), characterized by the lack of expression of the estrogen receptor, the progesterone receptor, and the human epidermal growth factor receptor 2, is an aggressive form of cancer that conveys unpredictable and poor prognosis due to limited treatment options and lack of effective targeted therapies. Wnt/β-catenin signaling is hyperactivated in TNBC, which promotes the progression of TNBC. However, the molecular mechanism of Wnt/β-catenin activation in TNBC remains unknown. Here, we report the drastic overexpression of miR-221/222 in all of four TNBC cell lines and TNBC primary tumor samples from patients. Furthermore, we demonstrate by both ex vivo and xenograft experiments that inhibiting miR-221/222 expression in a TNBC cell line (MDA-MB-231) suppresses its proliferation, viability, epithelial-to-mesenchymal transition, and migration; whereas expressing miR-221/222 in a non-TNBC line (MCF7) promotes all of the above cancer properties. miR-221/222 achieve so by directly repressing multiple negative regulators of the Wnt/β-catenin signaling pathway, including WIF1, SFRP2, DKK2, and AXIN2, to activate the pathway. Notably, the level of miR-221/222 expression is inversely correlated whereas that of WIF1, DKK2, SFRP2, and AXIN2 expression is positively correlated with the patient survival. Last, we show that anti-miR-221/222 significantly increases apoptotic cells with tamoxifen/Wnt3a treatment but not with cyclophosphamide/Wnt3a treatment. These results demonstrate that miR-221/222 activate the Wnt/β-catenin signaling to promote the aggressiveness and TNBC properties of breast cancers, and thus reveal a new prospect for TNBC treatment.

Oridonin synergistically enhances the anti-tumor efficacy of doxorubicin against aggressive breast cancer via pro-apoptotic and anti-angiogenic effects

The therapeutic outcomes of doxorubicin (Dox) treatment in breast cancer are limited by decreased drug efficiency and cardiotoxicity. The aim of this study was to investigate whether oridonin (Ori), a natural chemical abundant in the Chinese herb Isodon rubescens, might potentiate the anticancer effects, and decrease the adverse cardiotoxic effects, of Dox. On the basis of the optimized drug ratio determined through combination index calculations, we evaluated the synergistic effects and potential mechanisms of combining Dox with Ori to suppress breast cancer growth and angiogenesis both in vitro and in vivo. Dox plus Ori synergistically induced apoptosis in MDA-MB-231 cells, in a manner involving regulation of the Bcl-2/Bax, PARP, Caspase 3 and Survivin signaling pathways. Additionally, Ori increased the intracellular accumulation of Dox in MDA-MB-231 cells. Moreover, Dox plus Ori significantly decreased the proliferation, migration, invasion and tube formation of HUVECs. The underlying anti-angiogenic mechanism may have been due to the inhibition of VEGFR2-mediated signaling. Computational docking analysis further demonstrated that Dox plus Ori had high affinity toward the ATP-binding domain of VEGFR-2 kinase. Consistently with these findings, in vivo studies indicated that Ori enhanced the antitumor effect of Dox via activating apoptosis and inhibiting blood vessel formation at tumor sites. Moreover, Ori reversed the Dox-induced cardiotoxicity in a mouse model. In conclusion, our findings provide strong evidence that Ori may be highly promising in enhancing the efficacy of Dox and decreasing its adverse cardiotoxic effects, thus suggesting that Ori may serve as a potential adjunct therapy during Dox-based chemotherapy.

Tissue-Specific Chk1 Activation Determines Apoptosis by Regulating the Balance of p53 and p21

The DNA damage response (DDR) protects cells against genomic instability. Surprisingly, little is known about the differences in DDR across tissues, which may affect cancer evolutionary trajectories and chemotherapy response. Using mathematical modeling and quantitative experiments, we found that the DDR is regulated differently in human breast and lung primary cells. Equal levels of cisplatin-DNA lesions caused stronger Chk1 activation in lung cells, leading to resistance. In contrast, breast cells were more resistant and showed more Chk2 activation in response to doxorubicin. Further analyses indicate that Chk1 activity played a regulatory role in p53 phosphorylation, whereas Chk2 activity was essential for p53 activation and p21 expression. We propose a novel “friction model,” in which the balance of p53 and p21 levels contributes to the apoptotic response in different tissues. Our results suggest that modulating the balance of p53 and p21 dynamics could optimize the response to chemotherapy.

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Breast and lung cells show different sensitivities to chemotherapeutic drugs

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Lung cells activate Chk1 more strongly than breast cells with chemotherapeutic drugs

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Active Chk1 plays a regulatory role in p53 activation and apoptosis responses

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The balance of p53 and p21 dynamics drives the apoptosis response to DNA damage

Adjuvant therapy with stattic enriches the anti-proliferative effect of doxorubicin in human ZR-75-1 breast cancer cells via arresting cell cycle and inducing apoptosis

Adjuvant therapy with novel and effective component has been presented as a contrivance in breast cancer treatment versus the conventional methods. The current research was done to evaluate the implement of stattic, specific STAT3 inhibitor on the anti-proliferative and apoptotic behavior of doxorubicin on ZR-75-1 breast cancer cells. Cell viability was investigated by MTT assay, the percentage of apoptosis by DAPI staining, and Annexin V. Real Time-PCR was applied to find out the correlation between mechanistic roles of the STAT3 pathway and apoptotic signal in the modulation of Bcl-2 and Bax gene expressions axis. The IC50 values for doxorubicin and stattic were 2.5 ± 0.18 μM and 3.5 ± 0.28 μM, respectively. Combination index (CI) value for ZR-75-1 breast cancer was 0.72, which indicated a strong synergistic effect. Incubation of the cells with a combination of stattic and doxorubicin revealed a significant increase in growth inhibitory effect of doxorubicin with more than 50% decrease in proliferation rate and a two-fold increase in the percentage of apoptotic cells. Assessment of gene expression levels demonstrated a visible decrease in antiapoptotic Bcl-2 and Bcl-xl accompanied by an increase in pro-apoptotic Bax mRNA levels (p < 0.05). Taken together, our results show that combination of a STAT3 inhibitor and doxorubicin can be figured out as a promising approach for dealing of patients with breast cancers.

Small molecule inhibitors targeting the EGFR/ErbB family of protein-tyrosine kinases in human cancers

The EGFR family is among the most investigated receptor protein-tyrosine kinase groups owing to its general role in signal transduction and in oncogenesis. This family consists of four members that belong to the ErbB lineage of proteins (ErbB1-4). The ErbB proteins function as homo and heterodimers. These receptors contain an extracellular domain that consists of four parts: domains I and III are leucine-rich segments that participate in growth factor binding (except for ErbB2) and domains II and IV contain multiple disulfide bonds. Moreover, domain II participates in both homo and heterodimer formation within the ErbB/HER family of proteins. Seven ligands bind to EGFR including epidermal growth factor and transforming growth factor-α, none bind to ErbB2, two bind to ErbB3, and seven ligands bind to ErbB4. The extracellular domain is followed by a single transmembrane segment of about 25 amino acid residues and an intracellular portion of about 550 amino acid residues that contains (i) a short juxtamembrane segment, (ii) a protein kinase domain, and (iii) a carboxyterminal tail. ErbB2 lacks a known activating ligand and ErbB3 is kinase impaired. Surprisingly, the ErbB2-ErbB3 heterodimer complex is the most active dimer in the family. These receptors are implicated in the pathogenesis of a large proportion of lung and breast cancers, which rank first and second, respectively, in the incidence of all types of cancers (excluding skin) worldwide. On the order of 20% of non-small cell lung cancers bear activating mutations in EGFR. More than 90% of these patients have exon-19 deletions (⁷⁴⁶ELREA⁷⁵⁰) or the exon-21 L858R substitution. Gefitinib and erlotinib are orally effective type I reversible EGFR mutant inhibitors; type I inhibitors bind to an active enzyme conformation. Unfortunately, secondary resistance to these drugs occurs within about one year owing to a T790M gatekeeper mutation. Osimertinib is an irreversible type VI inhibitor that forms a covalent bond with C797 of EGFR and is FDA-approved for the treatment of patients with this mutation; type VI inhibitors generally form a covalent adduct with their target protein. Resistance also develops to this and related type VI inhibitory drugs owing to a C797S mutation; the serine residue is unable to react with the drugs to form a covalent bond. Approximately 20% of breast cancer patients exhibit ErbB2/HER2 gene amplification on chromosome 17q. One of the earliest targeted treatments in cancer involved the development of trastuzumab, a monoclonal antibody that interacts with the extracellular domain ErbB2/HER2 causing its down regulation. Surgery, radiation therapy, chemotherapy with cytotoxic drugs, and hormonal modulation are the mainstays in the treatment of breast cancer. Moreover, lapatinib and neratinib are FDA-approved small molecule ErbB2/HER2 antagonists used in the treatment of selected breast cancer patients. Of the approximate three dozen FDA-approved small molecule protein kinase inhibitors, five are type VI irreversible inhibitors and four of them including afatinib, osimertinib, dacomitinib, and neratinib are directed against the ErbB family of receptors (ibrutinib is the fifth and it targets Bruton tyrosine kinase). Avitinib, olmutinib, and pelitinib are additional type VI inhibitors in clinical trials for non-small cell lung cancer that target EGFR. Secondary resistance to both targeted and cytotoxic drugs is the norm, and devising and implementing strategies for minimizing or overcoming resistance is an important goal in cancer therapeutics.

Neoadjuvant chemotherapy regimens in treatment of breast cancer: a systematic review and network meta-analysis protocol

BACKGROUND

Neoadjuvant chemotherapy (NACT), a standard of care for locally advanced breast cancer patients, is widely used for early breast cancer patients also. The varying role of regimens used as NACT needs to be investigated. Despite availability of some randomized controlled trials (RCTs), it is unclear which treatment regimen suits best. Further, there is no study comparing all the three regimens. Accordingly, present study will compare the efficacy of anthracyclines, taxanes, and targeted therapy administered in neoadjuvant setting on the basis of oncological outcomes and functional outcomes.

METHOD/DESIGN

Online databases PubMed and Cochrane Register of Controlled Trials will be searched to acquire eligible studies. Further, content of relevant journals, references of relevant articles, and proceedings of major related conference will also be searched. The RCTs comparing any of abovementioned regimen as NACT on breast cancer patients will be eligible. Two reviewers independently and in duplicate will screen the records on the basis of title and abstract and complete full-text review to determine eligibility. Similarly, data extraction and risk of bias assessment will be done by two independent reviewers. The pair-wise meta-analysis as well as network meta-analysis will be conducted to assess the relative efficacy of anthracyclines, taxanes, and targeted therapy regimens.

DISCUSSION

The present systematic review will improve the understanding of the relative efficacies of the three treatment regimens and possibly guide the clinical practices by providing the current best evidence on the efficacy of various regimens of NACT in the management of breast cancer patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ( CRD42016027236 ).

A kinome-wide high-content siRNA screen identifies MEK5-ERK5 signaling as critical for breast cancer cell EMT and metastasis

An epithelial to mesenchymal transition (EMT) has been correlated to malignant tumor progression and metastasis by promoting cancer cell migration and invasion and chemoresistance. Hence, finding druggable EMT effectors is critical to efficiently interfere with metastasis formation and to overcome therapy resistance. We have employed a high-content microscopy screen in combination with a kinome and phosphatome-wide siRNA library to identify signaling pathways underlying an EMT of murine mammary epithelial cells and breast cancer cells. This screen identified the MEK5-ERK5 axis as a critical player in TGFβ-mediated EMT. Suppression of MEK5-ERK5 signaling completely prevented the morphological and molecular changes occurring during a TGFβ-induced EMT and, conversely, forced highly metastatic breast cancer cells into a differentiated epithelial state. Inhibition of MEK5-ERK5 signaling also repressed breast cancer cell migration and invasion and substantially reduced lung metastasis without affecting primary tumor growth. The results suggest that the MEK5-ERK5 signaling axis via activation of MEF2B and other transcription factors plays an important role in the induction and maintenance of breast cancer cell migration and invasion and thus represents an exploitable target for the pharmacological inhibition of cancer cell metastasis.

Dual or multi-targeting inhibitors: The next generation anticancer agents

Dual-targeting/Multi-targeting of oncoproteins by a single drug molecule represents an efficient, logical and alternative approach to drug combinations. An increasing interest in this approach is indicated by a steady upsurge in the number of articles on targeting dual/multi proteins published in the last 5 years. Combining different inhibitors that destiny specific single target is the standard treatment for cancer. A new generation of dual or multi-targeting drugs is emerging, where a single chemical entity can act on multiple molecular targets. Dual/Multi-targeting agents are beneficial for solving limited efficiencies, poor safety and resistant profiles of an individual target. Designing dual/multi-target inhibitors with predefined biological profiles present a challenge. The latest advances in bioinformatic tools and the availability of detailed structural information of target proteins have shown a way of discovering multi-targeting molecules. This neoteric artifice that amalgamates the molecular docking of small molecules with protein-based common pharmacophore to design multi-targeting inhibitors is gaining great importance in anticancer drug discovery. Current review focus on the discoveries of dual targeting agents in cancer therapy using rational, computational, proteomic, bioinformatics and polypharmacological approach that enables the discovery and rational design of effective and safe multi-target anticancer agents.

Combined Treatment with Stattic and Docetaxel Alters the Bax/Bcl-2 Gene Expression Ratio in Human Prostate Cancer Cells

Docetaxel, recognized as a stabilizing microtubule agent, is frequently administrated as a first line treatment for prostate cancers. Due to high side effects of monotherapy, however, combinations with novel adjuvants have emerged as an alternative strategy in cancer therapy protocols. Here, we investigated the combined effects of stattic and docetaxel on the DU145 prostate cancer cell line. Cytotoxicity was evaluated by MTT assay. To understand molecular mechanisms of stattic action, apoptotic related genes including Bcl-2, Mcl-1, Survivin and Bax were evaluated by real-time RT-PCR. Alteration in the expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 genes and Bax/Bcl-2 ratio were investigated via the 2^ΔΔCT method. The IC₅₀ values for docetaxel and stattic were 3.7 ± 0.9 nM and 4.6±0.8 µM, respectively. Evaluation of key gene expression levels revealed a noticeable decrease in antiapoptotic Bcl-2 and Mcl-1 along with an increase in pro-apoptotic Bax mRNA levels (p<0.05). Our results suggest that combination of a STAT3 inhibitor with doctaxel can be considered as a potent strategy for induction of apoptosis via increasing Bax mRNA expression.

Epithelial-to-mesenchymal transition is not required for lung metastasis but contributes to chemoresistance

The role of epithelial to mesenchymal transition (EMT) in metastasis is a longstanding source of controversy, largely due to an inability to monitor transient and reversible EMT phenotypes in vivo. We established an EMT lineage tracing system to monitor this process, using a mesenchymal-specific Cre-mediated fluorescent marker switch system in spontaneous breast-to-lung metastasis models. We confirmed that within a predominantly epithelial primary tumor, a small portion of tumor cells undergo EMT. Strikingly, lung metastases mainly consisted of non-EMT tumor cells maintaining their epithelial phenotype. Inhibiting EMT by overexpressing miR-200 did not impact lung metastasis development. However, EMT cells significantly contribute to recurrent lung metastasis formation after chemotherapy. These cells survived cyclophosphamide treatment due to reduced proliferation, apoptotic tolerance, and elevated expression of chemoresistance-related genes. Overexpression of miR-200 abrogated this resistance. This study suggests the potential of an EMT-targeting strategy, in conjunction with conventional chemotherapies, for breast cancer treatment.

Homoharringtonine induces apoptosis and inhibits STAT3 via IL-6/JAK1/STAT3 signal pathway in Gefitinib-resistant lung cancer cells

Tyrosine kinase inhibitors (TKIs) are mostly used in non-small cell lung cancer (NSCLC) treatment. Unfortunately, treatment with Gefitinib for a period of time will result in drug resistance and cause treatment failure in clinic. Therefore, exploring novel compounds to overcome this resistance is urgently required. Here we investigated the antitumor effect of homoharringtonine (HHT), a natural compound extracted from Cephalotaxus harringtonia, on Gefitinib-resistant NSCLC cell lines in vitro and in vivo. NCI-H1975 cells with EGFR T790M mutation are more sensitive to HHT treatment compared with that of A549 cells with wild type EGFR. HHT inhibited cells growth, cell viability and colony formation, as well as induced cell apoptosis through mitochondria pathway. Furthermore, we explored the mechanism of HHT inhibition on NSCLC cells. Higher level of interleukin-6 (IL-6) existed in lung cancer patients and mutant EGFR and TGFβ signal requires the upregulation of IL-6 through the gp130/JAK pathway to overactive STAT3, an oncogenic protein which has been considered as a potential target for cancer therapy. HHT reversiblely inhibited IL-6-induced STAT3 Tyrosine 705 phosphorylation and reduced anti-apoptotic proteins expression. Gefitinib-resistant NSCLC xenograft tests also confirmed the antitumor effect of HHT in vivo. Consequently, HHT has the potential in Gefitinib-resistant NSCLC treatment.

ASDCD: antifungal synergistic drug combination database

Finding effective drugs to treat fungal infections has important clinical significance based on high mortality rates, especially in an immunodeficient population. Traditional antifungal drugs with single targets have been reported to cause serious side effects and drug resistance. Nowadays, however, drug combinations, particularly with respect to synergistic interaction, have attracted the attention of researchers. In fact, synergistic drug combinations could simultaneously affect multiple subpopulations, targets, and diseases. Therefore, a strategy that employs synergistic antifungal drug combinations could eliminate the limitations noted above and offer the opportunity to explore this emerging bioactive chemical space. However, it is first necessary to build a powerful database in order to facilitate the analysis of drug combinations. To address this gap in our knowledge, we have built the first Antifungal Synergistic Drug Combination Database (ASDCD), including previously published synergistic antifungal drug combinations, chemical structures, targets, target-related signaling pathways, indications, and other pertinent data. Its current version includes 210 antifungal synergistic drug combinations and 1225 drug-target interactions, involving 105 individual drugs from more than 12,000 references. ASDCD is freely available at http://ASDCD.amss.ac.cn.

The ErbB/HER family of protein-tyrosine kinases and cancer

The human epidermal growth factor receptor (EGFR) family consists of four members that belong to the ErbB lineage of proteins (ErbB1-4). These receptors consist of a glycosylated extracellular domain, a single hydrophobic transmembrane segment, and an intracellular portion with a juxtamembrane segment, a protein kinase domain, and a carboxyterminal tail. Seven ligands bind to EGFR including epidermal growth factor and transforming growth factor α, none bind to ErbB2, two bind to ErbB3, and seven ligands bind to ErbB4. The ErbB proteins function as homo and heterodimers. The heterodimer consisting of ErbB2, which lacks a ligand, and ErbB3, which is kinase impaired, is surprisingly the most robust signaling complex of the ErbB family. Growth factor binding to EGFR induces a large conformational change in the extracellular domain, which leads to the exposure of a dimerization arm in domain II of the extracellular segment. Two ligand-EGFR complexes unite to form a back-to-back dimer in which the ligands are on opposite sides of the aggregate. Following ligand binding, EGFR intracellular kinase domains form an asymmetric homodimer that resembles the heterodimer formed by cyclin and cyclin-dependent kinase. The carboxyterminal lobe of the activator kinase of the dimer interacts with the amino-terminal lobe of the receiver kinase thereby leading to its allosteric stimulation. Downstream ErbB signaling modules include the phosphatidylinositol 3-kinase/Akt (PKB) pathway, the Ras/Raf/MEK/ERK1/2 pathway, and the phospholipase C (PLCγ) pathway. Several malignancies are associated with the mutation or increased expression of members of the ErbB family including lung, breast, stomach, colorectal, head and neck, and pancreatic carcinomas and glioblastoma (a brain tumor). Gefitinib, erlotinib, and afatinib are orally effective protein-kinase targeted quinazoline derivatives that are used in the treatment of ERBB1-mutant lung cancer. Lapatinib is an orally effective quinazoline derivative used in the treatment of ErbB2-overexpressing breast cancer. Trastuzumab, pertuzumab, and ado-trastuzumab emtansine, which are given intravenously, are monoclonal antibodies that target the extracellular domain and are used for the treatment of ErbB2-positive breast cancer; ado-trastuzumab emtansine is an antibody-drug conjugate that delivers a cytotoxic drug to cells overexpressing ErbB2. Cetuximab and panitumumab are monoclonal antibodies that target ErbB1 and are used in the treatment of colorectal cancer. Cancers treated with these targeted drugs eventually become resistant to them. The role of combinations of targeted drugs or targeted drugs with cytotoxic therapies is being explored in an effort to prevent or delay drug resistance in the treatment of these malignancies.

High-throughput screen identifies disulfiram as a potential therapeutic for triple-negative breast cancer cells: interaction with IQ motif-containing factors

Triple-negative breast cancer (TNBC) represents an aggressive subtype, for which radiation and chemotherapy are the only options. Here we describe the identification of disulfiram, an FDA-approved drug used to treat alcoholism, as well as the related compound thiram, as the most potent growth inhibitors following high-throughput screens of 3185 compounds against multiple TNBC cell lines. The average IC₅₀ for disulfiram was ~300 nM. Drug affinity responsive target stability (DARTS) analysis identified IQ motif-containing factors IQGAP1 and MYH9 as direct binding targets of disulfiram. Indeed, knockdown of these factors reduced, though did not completely abolish, cell growth. Combination treatment with 4 different drugs commonly used to treat TNBC revealed that disulfiram synergizes most effectively with doxorubicin to inhibit cell growth of TNBC cells. Disulfiram and doxorubicin cooperated to induce cell death as well as cellular senescence, and targeted the ESA⁺/CD24^-/low/CD44⁺ cancer stem cell population. Our results suggest that disulfiram may be repurposed to treat TNBC in combination with doxorubicin.

Tualang honey promotes apoptotic cell death induced by tamoxifen in breast cancer cell lines

Tualang honey (TH) is rich in flavonoids and phenolic acids and has significant anticancer activity against breast cancer cells comparable to the effect of tamoxifen (TAM), in vitro. The current study evaluated the effects of TH when used in combination with TAM on MCF-7 and MDA-MB-231 cells. We observed that TH promoted the anticancer activity of TAM in both the estrogen receptor-(ER-)responsive and ER-nonresponsive human breast cancer cell lines. Flow cytometric analyses indicated accelerated apoptosis especially in MDA-MB-231 cells and with the involvement of caspase-3/7, -8 and -9 activation as shown by fluorescence microscopy. Depolarization of the mitochondrial membrane was also increased in both cell lines when TH was used in combination with TAM compared to TAM treatment alone. TH may therefore be a potential adjuvant to be used with TAM for reducing the dose of TAM, hence, reducing TAM-induced adverse effects.

Progress and problems in the application of focused ultrasound for blood-brain barrier disruption

Advances in neuroscience have resulted in the development of new diagnostic and therapeutic agents for potential use in the central nervous system (CNS). However, the ability to deliver the majority of these agents to the brain is limited by the blood-brain barrier (BBB), a specialized structure of the blood vessel wall that hampers transport and diffusion from the blood to the brain. Many CNS disorders could be treated with drugs, enzymes, genes, or large-molecule biotechnological products such as recombinant proteins, if they could cross the BBB. This article reviews the problems of the BBB presence in treating the vast majority of CNS diseases and the efforts to circumvent the BBB through the design of new drugs and the development of more sophisticated delivery methods. Recent advances in the development of noninvasive, targeted drug delivery by MRI-guided ultrasound-induced BBB disruption are also summarized.

CE-LIF method for the separation of anthracyclines: application to protein binding analysis in plasma using ultrafiltration

Anthracyclines are chemotherapeutic drugs that are widely used in the treatment of cancers such as lung and ovarian cancers. The simultaneous determination of the anthracyclines, daunorubicin, doxorubicin and epirubicin, was achieved using CE coupled to LIF, with an excitation and emission wavelength of 488 and 560 nm, respectively. Using a borate buffer (105 mM, pH 9.0) and 30% MeOH, a stable and reproducible separation of the three anthracyclines was obtained. The method developed was shown to be capable of monitoring the therapeutic concentrations (50-50 000 ng/mL) of anthracyclines. LODs of 10 ng/mL, calculated at an S/N = 3, were achieved. Using the CE method developed, the in vitro protein binding to plasma was measured by ultrafiltration, and from this investigation the estimated protein binding was determined to be in the range of 77-94%.

Pegylated liposomal doxorubicin and gemcitabine in the front-line treatment of recurrent/metastatic breast cancer: a multicentre phase II study

This multicentre phase II study was aimed at investigating the activity and safety of pegylated liposomal doxorubicin (PLD) and gemcitabine (GEM) as front-line therapy in a large series of chemotherapy-naïve recurrent/metastatic breast cancer patients. From June 2003 to December 2006, a total of 71 recurrent/metastatic breast cancer patients were enrolled. Median age was 63 years (range=37-79), and 31 patients (43.7%) were > or =65 years old. Patients received PLD, 25 mg m(-2), day 1, followed by GEM, 800 mg m(-2), days 1 and 8, q21. Response was evaluable in 64 cases. Eight complete (12.5%) and 17 partial responses (26.6%) were registered, with an overall response rate of 39.1%. Thirty patients (46.9%) experienced stable disease, with an overall clinical benefit of 85.9%. Median time to progression (TTP) was 11 months, whereas median overall survival (OS) was not reached. The rate of 1- and 2-year OS was 79 and 61%, respectively. A total of 443 courses were evaluable for toxicity: grade 3 and 4 neutropaenia affected 14 patients (20.3%) and 3 patients (4.3%), respectively. Grade 3 and 4 palmar-plantar erythrodysesthesia syndrome was documented in five cases (7.2%) and one case (1.4%), whereas grade 3 and 4 mucositis occurred in six cases (8.7%) and two cases (2.9%), respectively. Grade 2 cardiac toxicity was observed in only one case. Interestingly enough, there was no difference in the percentage and severity of either haematological or non-haematological toxicity according to the age of the patients (<65 vs > or =65 years). We confirmed in a large, very homogenous study sample of chemotherapy-naïve recurrent/metastatic breast cancer patients the efficacy and safety of PLD/GEM combination, providing response rates, median TTP and OS values comparable with those achieved with more toxic combinations.

The novel combination of chlorpromazine and pentamidine exerts synergistic antiproliferative effects through dual mitotic action

Combination therapy has proven successful in treating a wide variety of aggressive human cancers. Historically, combination treatments have been discovered through serendipity or lengthy trials using known anticancer agents with similar indications. We have used combination high-throughput screening to discover the unexpected synergistic combination of an antiparasitic agent, pentamidine, and a phenothiazine antipsychotic, chlorpromazine. This combination, CRx-026, inhibits the growth of tumor cell lines in vivo more effectively than either pentamidine or chlorpromazine alone. Here, we report that CRx-026 exerts its antiproliferative effect through synergistic dual mitotic action. Chlorpromazine is a potent and specific inhibitor of the mitotic kinesin KSP/Eg5 and inhibits tumor cell proliferation through mitotic arrest and accumulation of monopolar spindles. Pentamidine treatment results in chromosomal segregation defects and delayed progression through mitosis, consistent with inhibition of the phosphatase of regenerating liver family of phosphatases. We also show that CRx-026 synergizes in vitro and in vivo with the microtubule-binding agents paclitaxel and vinorelbine. These data support a model where dual action of pentamidine and chlorpromazine in mitosis results in synergistic antitumor effects and show the importance of systematic screening for combinations of targeted agents.