Multiple drug resistance mechanisms in cancer. Mol Biotechnol. 2010;46:308-316. [PMID: 20717753 DOI: 10.1007/s12033-010-9321-2]

Improvement of conventional anti-cancer drugs as new tools against multidrug resistant tumors

Multidrug resistance (MDR) is the dominant cause of the failure of cancer chemotherapy. The design of antitumor drugs that are able to evade MDR is rapidly evolving, showing that this area of biomedical research attracts great interest in the scientific community. The current review explores promising recent approaches that have been developed with the aim of circumventing or overcoming MDR. Encouraging results have been obtained in the investigation of the MDR-modulating properties of various classes of natural compounds and their analogues. Inhibition of P-gp or downregulation of its expression have proven to be the main mechanisms by which MDR can be surmounted. The use of hybrid molecules that are able to simultaneously interact with two or more cancer cell targets is currently being explored as a means to circumvent drug resistance. This strategy is based on the design of hybrid compounds that are obtained either by merging the structural features of separate drugs, or by conjugating two drugs or pharmacophores via cleavable/non-cleavable linkers. The approach is highly promising due to the pharmacokinetic and pharmacodynamic advantages that can be achieved over the independent administration of the two individual components. However, it should be stressed that the task of obtaining successful multivalent drugs is a very challenging one. The conjugation of anticancer agents with nitric oxide (NO) donors has recently been developed, creating a particular class of hybrid that can combat tumor drug resistance. Appropriate NO donors have been shown to reverse drug resistance via nitration of ABC transporters and by interfering with a number of metabolic enzymes and signaling pathways. In fact, hybrid compounds that are produced by covalently attaching NO-donors and antitumor drugs have been shown to elicit a synergistic cytotoxic effect in a variety of drug resistant cancer cell lines. Another strategy to circumvent MDR is based on nanocarrier-mediated transport and the controlled release of chemotherapeutic drugs and P-gp inhibitors. Their pharmacokinetics are governed by the nanoparticle or polymer carrier and make use of the enhanced permeation and retention (EPR) effect, which can increase selective delivery to cancer cells. These systems are usually internalized by cancer cells via endocytosis and accumulate in endosomes and lysosomes, thus preventing rapid efflux. Other modalities to combat MDR are described in this review, including the pharmaco-modulation of acridine, which is a well-known scaffold in the development of bioactive compounds, the use of natural compounds as means to reverse MDR, and the conjugation of anticancer drugs with carriers that target specific tumor-cell components. Finally, the outstanding potential of in silico structure-based methods as a means to evaluate the ability of antitumor drugs to interact with drug transporters is also highlighted in this review. Structure-based design methods, which utilize 3D structural data of proteins and their complexes with ligands, are the most effective of the in silico methods available, as they provide a prediction regarding the interaction between transport proteins and their substrates and inhibitors. The recently resolved X-ray structure of human P-gp can help predict the interaction sites of designed compounds, providing insight into their binding mode and directing possible rational modifications to prevent them from becoming P-gp drug substrates. In summary, although major efforts were invested in the search for new tools to combat drug resistant tumors, they all require further implementation and methodological development. Further investigation and progress in the abovementioned strategies will provide significant advances in the rational combat against cancer MDR.

Alleviation of Multidrug Resistance by Flavonoid and Non-Flavonoid Compounds in Breast, Lung, Colorectal and Prostate Cancer

The aim of the manuscript is to discuss the influence of plant polyphenols in overcoming multidrug resistance in four types of solid cancers (breast, colorectal, lung and prostate cancer). Effective treatment requires the use of multiple toxic chemotherapeutic drugs with different properties and targets. However, a major cause of cancer treatment failure and metastasis is the development of multidrug resistance. Potential mechanisms of multidrug resistance include increase of drug efflux, drug inactivation, detoxification mechanisms, modification of drug target, inhibition of cell death, involvement of cancer stem cells, dysregulation of miRNAs activity, epigenetic variations, imbalance of DNA damage/repair processes, tumor heterogeneity, tumor microenvironment, epithelial to mesenchymal transition and modulation of reactive oxygen species. Taking into consideration that synthetic multidrug resistance agents have failed to demonstrate significant survival benefits in patients with different types of cancer, recent research have focused on beneficial effects of natural compounds. Several phenolic compounds (flavones, phenolcarboxylic acids, ellagitannins, stilbens, lignans, curcumin, etc.) act as chemopreventive agents due to their antioxidant capacity, inhibition of proliferation, survival, angiogenesis, and metastasis, modulation of immune and inflammatory responses or inactivation of pro-carcinogens. Moreover, preclinical and clinical studies revealed that these compounds prevent multidrug resistance in cancer by modulating different pathways. Additional research is needed regarding the role of phenolic compounds in the prevention of multidrug resistance in different types of cancer.

Antiproliferative activities of tricyclic amides derived from β-caryophyllene via the Ritter reaction against MDA-MB-231 breast cancer cells

A library of novel tricyclic amides has been synthesised via the Ritter reaction from β-caryophyllene 1 and its monoepoxy derivative 4. The compounds were assessed for antiproliferative activities against the aggressive MDA-MB-231 breast cancer cell line. Of the synthesised compounds, eight were active. 3c and 6b were the most potent and inhibited proliferation with IC₅₀ of 9.7 and 8.2 μM, respectively. Mechanistic studies revealed differences in their antiproliferative actions. 6b inhibited cell cycle progression and induced predominantly apoptotic cell death. In contrast, 3c did not affect cell cycle kinetics and favoured necrotic over apoptotic pathways. Screening against mammalian cells (VERO cells) indicates that 3c and 6b were more active towards MDA-MB-231 cells than noncancerous cells. Facile synthesis and biological results suggest that these caryophyllene derived amides are viable lead compounds for further development.

A siramesine-loaded metal organic framework nanoplatform for overcoming multidrug resistance with efficient cancer cell targeting

ZIF-8@Sira/FA induces the cancer cells apoptosis and then eliminates cancer cells from the inside through the lysosomal death pathway.

Dihydroartemisinin Sensitizes Mutant p53 (R248Q)-Expressing Hepatocellular Carcinoma Cells to Doxorubicin by Inhibiting P-gp Expression

Mutant p53 (R248Q) induces doxorubicin (ADM) resistance in hepatocellular carcinoma (HCC). Dihydroartemisinin (DHA) can synergistically enhance anticancer effect of many chemotherapeutic agents. However, whether DHA could increase therapeutic efficacy of ADM in p53 (R248Q)-expressing HCC cells remains unknown. In the present study, we established mutant p53 (R248Q)-expressing Hep3B cells to study the effect and mechanism of DHA on ADM resistance and the synergistic effect of DHA with ADM. We found that P-gp was highly expressed in p53 (R248Q)-expressing Hep3B cells. As a result, cells expressing p53 (R248Q) displayed higher cell viability and lower cell apoptosis level upon ADM treatment. Meanwhile, phosphorylation levels of ERK1/2 and p65 were elevated in p53 (R248Q)-expressing Hep3B cells. However, combination of DHA and ADM treatment decreased cell viability and elevated cell apoptosis level in p53 (R248Q)-expressing Hep3B cells. Molecular dynamics simulations showed that DHA had the potential to bind with mutant p53 (R248Q) protein. Furthermore, DHA treatment decreased P-gp expression and inhibited phosphorylation levels of ERK1/2 and p65 in p53 (R248Q)-expressing Hep3B cells. Finally, DHA treatment could significantly reduce ADM efflux in p53 (R248Q)-expressing cells. Our results indicate that DHA could decrease P-gp expression via inhibiting the p53 (R248Q)-ERK1/2-NF-κB signaling pathway, which eventually confers sensitization of p53 (R248Q)-expressing HCC cells to ADM. Our study provides evidence for the potential application of DHA and ADM combination in treatment of mutant p53 (R248Q)-harbored HCC.

Cold Atmospheric Plasma Restores Paclitaxel Sensitivity to Paclitaxel-Resistant Breast Cancer Cells by Reversing Expression of Resistance-Related Genes

Paclitaxel (Tx) is a widely used therapeutic chemical for breast cancer treatment; however, cancer recurrence remains an obstacle for improved prognosis of cancer patients. In this study, cold atmospheric plasma (CAP) was tested for its potential to overcome the drug resistance. After developing Tx-resistant MCF-7 (MCF-7/TxR) breast cancer cells, CAP was applied to the cells, and its effect on the recovery of drug sensitivity was assessed in both cellular and molecular aspects. Sensitivity to Tx in the MCF-7/TxR cells was restored up to 73% by CAP. A comparison of genome-wide expression profiles between the TxR cells and the CAP-treated cells identified 49 genes that commonly appeared with significant changes. Notably, 20 genes, such as KIF13B, GOLM1, and TLE4, showed opposite expression profiles. The protein expression levels of selected genes, DAGLA and CEACAM1, were recovered to those of their parental cells by CAP. Taken together, CAP inhibited the growth of MCF-7/TxR cancer cells and recovered Tx sensitivity by resetting the expression of multiple drug resistance–related genes. These findings may contribute to extending the application of CAP to the treatment of TxR cancer.

Cell Cycle Inhibition and Apoptotic Induction of Vernonia amygdalina Del. Leaves Extract on MCF-7 Cell Line

AIM:

The research aimed to determine the cytotoxic activity, cell cycle inhibition, and apoptosis induction of the ethyl acetate extract of the African leaves Vernonia amygdalina Del. on the MCF-7 cancer cells.

METHODS:

The extraction of Vernonia amygdalina Del. leaves was done using the maceration method whereas the cytotoxic was performed using MTT assay. After that, the cell cycle testing and apoptosis induction were conducted using flow cytometry assay.

RESULTS:

The IC₅₀ values of n-hexane, ethyl acetate, and ethanol extract of Vernonia amygdalina Del. on the MCF-7 cancer cells were 206.211 ± 0.99, 50,365 ± 0.07, and 967.033 ± 2.68 µg/mL, respectively. The percentage of the cycle cell results in the G₀-G₁ phase in the cell control with 72.08% decreased in the treatment with ethyl acetate extract 1/2 IC₅₀ with 62.58% and 1/5 IC₅₀ with 44.72%. For the S and G2-M phase, the highest percentage was found in the ethyl acetate extract 1/5 IC₅₀ treatment with 47.27% and 9.50% which were higher than the control cells with 23.26% and 5.90%.

CONCLUSION:

Based on the results, the Vernonia amygdalina Del. extract provides chemopreventive agent as anti-cancer. Our future study will assess the mechanism of ethyl acetate fraction in inhibiting angiogenesis and metastatic in breast cancer.

Imatinib enhances the anti-tumour effect of doxorubicin in canine B-cell lymphoma cell line

Canine lymphoma is one of the most common malignant tumours occurring in dogs and has a high incidence worldwide. Despite advances in cancer prevention, the treatment of neoplastic diseases still requires improvement. Some cancer cells may resist the effect of chemotherapeutic agents by up-regulating drug transporters leading to increased drug efflux, resulting in intrinsic or acquired drug resistance, which is a mechanism commonly seen in doxorubicin-resistant tumour cells. In this study, canine B-cell lymphoma cell line CLBL1-8.0, a doxorubicin-resistant B cell lymphoma cell line derived from CLBL-1 by increasing the doxorubicin concentration during culturing, exhibited high expression of P-glycoprotein (P-gp, ATP-binding cassette sub-family B member 1 [ABCB1]). These proteins are commonly involved in cancer cell resistance to doxorubicin. Imatinib, a tyrosine kinase inhibitor significantly potentiated the sensitivity of doxorubicin in P-gp-overexpressing doxorubicin-resistant cells. Moreover, a combination of these two drugs may increase the retention of doxorubicin by decreasing the efflux of doxorubicin without affecting P-gp protein overexpression. In conclusion, imatinib reversed doxorubicin resistance by decreasing drug efflux in P-gp-overexpressing doxorubicin-resistant canine lymphoma cells. These results suggest that combining doxorubicin, one of the most widely used chemotherapeutic drugs in the treatment of canine lymphoma, with imatinib might potentially overcome doxorubicin resistance in a clinical setting.

The secondary metabolites produced by Lactobacillus plantarum downregulate BCL-2 and BUFFY genes on breast cancer cell line and model organism Drosophila melanogaster: molecular docking approach

PURPOSE

The current study was designed to evaluate the toxicity of the secondary metabolites of Lactobacillus plantarum against the human breast cancer cell line (MCF-7) and the Drosophila melanogaster.

METHODS

In this study, toxicity analyses of secondary metabolites of Lactobacillus plantarum were analyzed on breast cancer cells, and the Drosophila melanogaster. After application, in the MCF-7 cell line, expression levels of RRAS-2, TP53, BCL-2, APAF-1, CASP-3, FADD, CASP-7, BOK genes; in D. melanogaster; expression levels of RAS64B P53, BUFFY, DARK, DECAY, FADD, DRICE, and DEBCL genes were determined by RT-PCR. In addition, analysis of L. plantarum secondary metabolite was performed by GC-MS method and molecular binding poses of secondary metabolites and human enzymes were investigated in silico.

RESULTS

Drosophila melanogaster being used as a model organism where some of the human genes were preserved. The IC50 value of the secondary metabolite in the MCF-7 cell line was determined to be 0.0011 mg/ml. Lethal concentration 50 (LC₅₀) and 99 (LC₉₉) values of secondary metabolites against fruit fly adults were 0.24 mg/ml and 0.54 mg/ml, respectively. The expression levels of BCL-2 and BUFFY genes which are anti-apoptotic in human and fruit flies have been reduced, and at the same time, increased expression of DECAY, FADD, RAS64B apoptotic genes in D. melanogaster.

CONCLUSION

The substance detected in the secondary metabolite content and encoded as L13 (3-phenyl-1, 2, 4-benzotriazine) has been observed to have high binding affinity in the studied genes.

Clinical Theragnostic Relationship between Drug-Resistance Specific miRNA Expressions, Chemotherapeutic Resistance, and Sensitivity in Breast Cancer: A Systematic Review and Meta-Analysis

Awareness of breast cancer has been increasing due to early detection, but the advanced disease has limited treatment options. There has been growing evidence on the role of miRNAs involved in regulating the resistance in several cancers. We performed a comprehensive systematic review and meta-analysis on the role of miRNAs in influencing the chemoresistance and sensitivity of breast cancer. A bibliographic search was performed in PubMed and Science Direct based on the search strategy, and studies published until December 2018 were retrieved. The eligible studies were included based on the selection criteria, and a detailed systematic review and meta-analysis were performed based on PRISMA guidelines. A random-effects model was utilised to evaluate the combined effect size of the obtained hazard ratio and 95% confidence intervals from the eligible studies. Publication bias was assessed with Cochran’s Q test, I² statistic, Orwin and Classic fail-safe N test, Begg and Mazumdar rank correlation test, Duval and Tweedie trim and fill calculation and the Egger’s bias indicator. A total of 4584 potential studies were screened. Of these, 85 articles were eligible for our systematic review and meta-analysis. In the 85 studies, 188 different miRNAs were studied, of which 96 were upregulated, 87 were downregulated and 5 were not involved in regulation. Overall, 24 drugs were used for treatment, with doxorubicin being prominently reported in 15 studies followed by Paclitaxel in 11 studies, and 5 drugs were used in combinations. We found only two significant HR values from the studies (miR-125b and miR-4443) and our meta-analysis results yielded a combined HR value of 0.748 with a 95% confidence interval of 0.508–1.100; p-value of 0.140. In conclusion, our results suggest there are different miRNAs involved in the regulation of chemoresistance through diverse drug genetic targets. These biomarkers play a crucial role in guiding the effective diagnostic and prognostic efficiency of breast cancer. The screening of miRNAs as a theragnostic biomarker must be brought into regular practice for all diseases. We anticipate that our study serves as a reference in framing future studies and clinical trials for utilising miRNAs and their respective drug targets.

Dietary Compounds for Targeting Prostate Cancer

Prostate cancer is the third most common cancer worldwide, and the burden of the disease is increased. Although several chemotherapies have been used, concerns about the side effects have been raised, and development of alternative therapy is inevitable. The purpose of this study is to prove the efficacy of dietary substances as a source of anti-tumor drugs by identifying their carcinostatic activities in specific pathological mechanisms. According to numerous studies, dietary substances were effective through following five mechanisms; apoptosis, anti-angiogenesis, anti-metastasis, microRNA (miRNA) regulation, and anti-multi-drug-resistance (MDR). About seventy dietary substances showed the anti-prostate cancer activities. Most of the substances induced the apoptosis, especially acting on the mechanism of caspase and poly adenosine diphosphate ribose polymerase (PARP) cleavage. These findings support that dietary compounds have potential to be used as anticancer agents as both food supplements and direct clinical drugs.

In vivo acute toxicity evaluation and in vitro molecular mechanism study of antiproliferative activity of a novel indole Schiff base β-diiminato manganeseIII complex in hormone-dependent and triple negative breast cancer cells

Breast cancer is the most frequently diagnosed cancer among women worldwide. Recently, increasing attention has been paid to the anticancer effects of transition metal complexes of indole Schiff bases. β-diiminato Manganese^III complex has shown promising cell cycle arrest and apoptosis induction against MCF-7 and MDA-MB-231 breast cancer cells. In this study, time- and dose- dependent inhibitory activity were evaluated using MTT assay after 48 h and 72 h exposure time. In addition, median effect analysis was conducted according to Chou-Talalay method to investigate whether Mn^III complex has synergistic effect in combination with chemotherapeutic drugs on inhibiting breast cancer cell growth. The molecular mechanisms underlying its potent antiproliferative effect was determined through bioluminescent caspase-3/7, -8 and -9 activity assays and quantitative expression analysis of cell cycle- and apoptosis-related genes. Furthermore, safety evaluation of Mn^III complex was assessed through the acute oral toxicity test in in vivo model. The MTT assay results revealed that it potently reduced the viability of MCF-7 (IC₅₀ of 0.63 ± 0.07 µg/mL for 48 h and 0.39 ± 0.08 µg/mL for 72 h) and MDA-MB-231 (1.17 ± 0.06 µg/mL for 48 h, 1.03 ± 0.15 µg/mL for 72 h) cells in dose- and time-dependent manner. Combination treatment also enhanced the cytotoxic effects of doxorubicin but not tamoxifen on inhibiting breast cancer cell growth. The involvement of intrinsic and extrinsic pathway in apoptosis induction was exhibited through the increased activity of caspase-9 and caspase-8, respectively, leading to enhanced downstream executioner caspase-3/7 activity in treated MCF-7 and MDA-MB-231 cells. In addition, gene expression analysis revealed that Mn^III complex exerts its antiproliferative effect via up-and down-regulation of p21 and cyclin D1, respectively, along with increased expression of Bax/Bcl-2 ratio, TNF-α, initiator caspase-8 and -10 and effector caspase-3 in MCF-7 and MDA-MB-231 cells. However, the results did not show increased caspase-8 activity in treated MCF-7 cells. Furthermore, in vivo acute oral toxicity test revealed no signs of toxicity and mortality in treated animal models compared to the control group. Collectively, the promising inhibitory effect and molecular and mechanistic evidence of antiproliferative activity of Mn^III complex and its safety characterization have demonstrated that it may have therapeutic value in breast cancer treatment worthy of further investigation and development.

Concurrent targeting of BMI1 and CDK4/6 abrogates tumor growth in vitro and in vivo

Despite recent advances in cancer management and therapy, resistance to cytotoxic medications remains a major clinical challenge; hence, combination-based anti-cancer treatment regimens are currently gaining momentum. PTC-209 reduced BMI1 protein expression, while palbociclib inhibited CDK4, Rb, and pRb^Ser795 protein expression in MDA-MB-231 cells. PTC-209 and palbociclib exhibited dose-dependent cytotoxic effects against MDA-MB-231 (breast), HCT116 (colon), and PC-3 (prostate) models, which was more profound in the combination group. Transcriptome and pathway analyses revealed inhibition of insulin signaling, focal adhesion, DNA damage response, and Wnt/pluripotency signaling pathways as well as cell proliferation, and cellular movement functional categories by PTC-209. Transcriptome and pathway analyses revealed palbociclib to mainly affect cell cycle progression and survival. Upstream analysis identified several networks affected by PTC-209 (EZH2, IFNB1, TRIB3, EGFR, SREBF1, IL1A, ERG, TGFB1, MAX, MNT) and palbociclib (RABL6, MITF, RARA, TAL1, AREG, E2F3, FOXM1, ESR1, ERBB2, and E2F). PTC-209 and palbociclib reduced colony and sphere formation, cell migration, and cell viability, which was further enhanced in the combination group. Concordantly, combination of PTC-209 and palbociclib exhibited more profound effects on MDA-MB-231 tumor formation in vivo. Our data suggest concurrent targeting of BMI1 and CDK4/CDK6 might provide novel therapeutic opportunity for breast, colon, and prostate cancer.

Conformational equilibrium defines the variable induction of the multidrug-binding transcriptional repressor QacR

QacR, a multidrug-binding transcriptional repressor in pathogenic bacteria Staphylococcus aureus, modulates the transcriptional level of the multidrug transporter gene, qacA, in response to engaging a set of diverse ligands. However, the structural basis that defines the variable induction level remains unknown. Here, we reveal that the conformational equilibrium between the repressive and inducive conformations in QacR defines the induction level of the transporter gene. In addition, the unligated QacR is already partly populated in the inducive conformation, allowing the basal expression of the transporter. We also showed that, in the known constitutively active QacR mutants, the equilibrium is shifted more toward the inducive conformation, even in the unligated state. These results highlight the unexpected structural mechanism, connecting the promiscuous multidrug binding to the variable transcriptional regulation of QacR, which provide clues to dysfunctioning of the multidrug resistance systems.

Chk1 Inhibitor MK-8776 Restores the Sensitivity of Chemotherapeutics in P-glycoprotein Overexpressing Cancer Cells

P-glycoprotein (P-gp), which is encoded by the ATP-binding cassette (ABC) transporter subfamily B member 1 (ABCB1) gene, is one of the most pivotal ABC transporters that transport its substrates across the cell membrane. Its overexpression is one of the confirmed causes of multidrug resistance (MDR), which results in the failure of cancer treatment. Here, we report that checkpoint kinase (Chk) 1 inhibitor MK-8776, a drug candidate in clinical trial, can restore the sensitivity of chemotherapeutics that are substrates of P-gp in KB-C2, SW620/Ad300 cells and human embryonic kidney (HEK)293/ABCB1 cells that overexpress P-gp. MK-8776 remarkably enhanced the cellular [³H]-paclitaxel accumulation and suppressed the efflux function of P-gp without reducing its expression and affecting its cellular localization in cancer cells. Furthermore, MK-8776 (0–40 μM) stimulated the activity of ATPase in P-gp, which was 4.1-fold greater than the control. In addition, MK-8776 formed a cation–π bond and π–π interaction with key residues of the substrate-binding site in P-gp, as indicated by computer-aided molecular docking study. Our study indicated that MK-8776 may significantly enhance the sensitivity of chemotherapeutics that are substrates of P-gp, providing important information for its application in the reversal of MDR.

4(1H)-quinolone derivatives overcome acquired resistance to anti-microtubule agents by targeting the colchicine site of β-tubulin

Developing new therapeutic strategies to overcome drug resistance of cancer cells is an ongoing endeavor. From among 2 million chemicals, we identified ethyl 4-oxo-2-phenyl-1,4-dihydroquinoline-6-carboxylate (AS1712) as a low-toxicity inhibitor of lung cancer cell proliferation and xenograft tumor growth. We show that AS1712 is active against broad cancer cell lines and is able to bind in the colchicine-binding pocket of β-tubulin, thereby inhibiting microtubule assembly and, consequently, inducing mitotic arrest and apoptosis. Our cell-based structure-activity relationship study identified a new lead compound, RJ-LC-15-8, which had a greater anti-proliferative potency for H1975 cells than did AS1712, while maintaining a similar mechanism of action. Notably, AS1712 and RJ-LC-15-8 overcame P-glycoprotein efflux pump and β-tubulin alterations that lead to acquired resistance against microtubule-targeting drugs of cancer cells. AS1712 and RJ-LC-15-8 may be lead compounds that overcome acquired resistance to microtubule-targeting agents of cancer cells.

ABC Transporters: Regulation and Association with Multidrug Resistance in Hepatocellular Carcinoma and Colorectal Carcinoma

For most cancers, the treatment of choice is still chemotherapy despite its severe adverse effects, systemic toxicity and limited efficacy due to the development of multidrug resistance (MDR). MDR leads to chemotherapy failure generally associated with a decrease in drug concentration inside cancer cells, frequently due to the overexpression of ABC transporters such as P-glycoprotein (P-gp/MDR1/ABCB1), multidrug resistance-associated proteins (MRPs/ABCCs), and breast cancer resistance protein (BCRP/ABCG2), which limits the efficacy of chemotherapeutic drugs. The aim of this review is to compile information about transcriptional and post-transcriptional regulation of ABC transporters and discuss their role in mediating MDR in cancer cells. This review also focuses on drug resistance by ABC efflux transporters in cancer cells, particularly hepatocellular carcinoma (HCC) and colorectal carcinoma (CRC) cells. Some aspects of the chemotherapy failure and future directions to overcome this problem are also discussed.

Transgelin-2 expression in breast cancer and its relationships with clinicopathological features and patient outcome

BACKGROUND

Transgelin-2 is an actin-binding protein that is widely expressed in various tissues and organs of the body, and reportedly may participate in the development and progression of multiple cancers. However, the clinical significance of transgelin-2 still remains controversial. We, therefore, aimed to determine the expression of transgelin-2 in breast cancer as well as its correlation with the tumorigenesis, progression and prognosis of human breast cancer.

METHODS

We collected tissues of 58 breast cancer patients from our hospital and 1090 samples from The Cancer Genome Atlas (TCGA) database. X-tile software was used to divide the transgelin-2 mRNA expression level in the database, logistic regression model was used to identify independent factors influencing transgelin-2 mRNA expression, and then Cox regression and Kaplan-Meier analysis were used to find factors that influence survival of breast cancer.

RESULTS

Transgelin-2 was significantly overexpressed in breast cancer tissues from our hospital and receiver operating characteristic (ROC) curve indicated that transgelin-2 may have diagnostic value. Meanwhile, estrogen receptor (ER) was in inverse correlation with transgelin-2 protein and mRNA expression, and transgelin-2 expression was positively correlated with Ki67 in breast cancer tissues. Logistic regression model revealed that TNM stage, ER and progesterone receptor (PR) status were independent factors for transgelin-2 mRNA expression. Patients with high transgelin-2 mRNA expression showed a poor survival and the trend was statistically significant only in ER-negative patients.

CONCLUSIONS

Transgelin-2 was expressed significantly higher in breast cancer cells and correlated with some clinicopathological factors. High transgelin-2 expression might predict poor prognosis for ER-negative patients.

Targeting MCF-7 Cell Line by Listeriolysin O Pore Forming Toxin Fusion with AHNP Targeted Peptide

Background

Tumor-targeting peptides are attracting subjects in cancer therapy. These peptides, which are widely studied, deliver therapeutic agents to the specific sites of tumors. In this study, we produced a new form of recombinant listeriolysin O (LLO) with genetically fused Anti-HER2/neu peptide (AHNP) sequence adding to its C-terminal end. The aim of the study was to engineer this pore-forming toxin to make it much more specific to tumor cells.

Materials and Method and Results

Two forms of the toxin (with and without peptide) were subcloned into a bacterial expression plasmid. Subcloning was performed using a polymerase chain reaction (PCR) product as a megaprimer in a quick-change PCR to introduce the whole insert gene into the expression plasmid. After expression of two recombinant forms of LLO in BL21 DE3 cells, purification was performed using Ni-NTA affinity column. MDA-MB-231 and MCF-7 cell lines (as negative and positive controls, respectively) were treated with both LLO toxins to evaluate their cytotoxicity and specificity. The IC₅₀ of LLO on MDA-MB-231 and MCF-7 cells was 21 and 5 ng/ml, respectively. In addition, IC₅₀ for the fusion AHNP-LLO toxin was 140 and 60 ng/ml, respectively. It was found that the cytotoxicity of the new engineered AHNP-LLO toxin has decreased by about 9x compared to the wild-type toxin and the specificity of the AHNP-LLO toxin has been also reduced.

Conclusions

Results show that the C-terminal of the LLO should not be modified and it seems that N-terminal of the toxin should be preferred for engineering and adding peptide modules.

miR-1271 enhances the sensitivity of colorectal cancer cells to cisplatin

The high mortality of colorectal cancer (CRC) is likely caused by early invasion and metastasis. The chemoresistance of tumor cells is the critical reason for treatment failure. The present study aimed to develop targeted solutions to overcome chemotherapy drug resistance in CRC. CCK-8 assay was used to examine SW480 cell viability. SW480 cell apoptosis was examined using flow cytometry. The present study demonstrated that the expression of miR-1271 was significantly decreased in CRC tumors and cell lines compared with control tissues. Furthermore, the expression of microRNA (miR)-1271 was increased and decreased following the transfection of miR-1271 mimics and an inhibitor, respectively. Furthermore, miR-1271 regulated mammalian target of rapamycin (mTOR) expression by directly binding to the mTOR 3'-untranslated region and the relative luciferase activity of mTOR was decreased following miR-1271 overexpression. The results of the present study indicate that miR-1271 may be a potential target for anti-CRC therapy, particularly in the sensitivity of chemotherapeutic drugs. miR-1271 may therefore enhance the sensitivity of CRC cells to chemotherapy drugs and provide a novel approach for the gene therapy of CRC.

SMAD3 silencing enhances DNA damage in radiation therapy by interacting with MRE11-RAD50-NBS1 complex in glioma

Radiotherapy is the major treatment modality for malignant glioma. However, the treatment response of radiotherapy is suboptimal due to resistance. Here we aimed to explore the effect and mechanism of Mothers against decapentaplegic homologue (SMAD3) silencing in sensitizing malignant glioma to radiotherapy. Clonogenic assay was used to evaluate the sensitivity of glioma cells to increasing doses of radiation. Glioma cells were transfected with small-interfering RNAs (siRNAs) specific to SMAD3. Overexpression of SMAD3 was achieved by transfecting expression plasmid encoding SMAD3 cDNA. Changes in MRE11-RAD50-NBS1 mRNA and protein levels were assessed through qPCR analysis and western blot analysis, respectively. Chromatin immunoprecipitation (ChIP) was used to confirm the interaction between SMAD3 and MRE11-RAD50-NBS1 (MRN) complex. Silencing of SMAD3 increased sensitivity of glioma cells to radiotherapy. MRE11, RAD50 and NBS1 were overexpressed in response to radiotherapy, which was attenuated by SMAD3 silencing while boosted by SMAD3 overexpression. ChIP analysis confirmed the interaction of SMAD3 with MRE11, RAD50 and NBS1 under radiotherapy, which was inhibited by SMAD3 silencing. SMAD3 silencing is an effective strategy for sensitizing glioma to radiotherapy, which is mediated by the interaction of SMAD3 with the MRN complex.

Comprehensive analysis of circular RNAs in pathological states: biogenesis, cellular regulation, and therapeutic relevance

Circular RNAs (circRNAs) are members of the non-coding transcriptome; however, some of them are translated into proteins. These transcripts have important roles in both physiological and pathological mechanisms due to their ability to directly influence cellular signaling pathways. Specifically, circRNAs are regulators of transcription, translation, protein interaction, and signal transduction. An increased knowledge within their area is observed over the last few years, concomitant with the development of next-generation sequencing techniques. circRNAs are mostly tissue and disease specific with the ability of specifically changing the biological behavior of cells. The altered expression profile is currently investigated as novel minimally invasive diagnosis/prognosis tool and also therapeutic target in human disease. The diagnosis approach is based on their level modification within pathological states, especially cancer, where circRNAs' therapies are intensively explored in anti-aging strategies, diabetes, cardiovascular diseases, and malignant pathologies, and are relying on the restoration of homeostatic profiles.

Iron Metabolism in Liver Cancer Stem Cells

Cancer stem cells (CSC) which have been identified in several tumors, including liver cancer, represent a particular subpopulation of tumor cells characterized by properties similar to those of adult stem cells. Importantly, CSC are resistant to standard therapies, thereby leading to metastatic dissemination and tumor relapse. Given the increasing evidence that iron homeostasis is deregulated in cancer, here we describe the iron homeostasis alterations in cancer cells, particularly in liver CSC. We also discuss two paradoxically opposite iron manipulation-strategies for tumor therapy based either on iron chelation or iron overload-mediated oxidant production leading to ferroptosis. A better understanding of iron metabolism modifications occurring in hepatic tumors and particularly in liver CSC cells may offer new therapeutic options for this cancer, which is characterized by increasing incidence and unfavorable prognosis.

The role and mechanisms of action of microRNAs in cancer drug resistance

MicroRNAs (miRNAs) are small non-coding RNAs with a length of about 19–25 nt, which can regulate various target genes and are thus involved in the regulation of a variety of biological and pathological processes, including the formation and development of cancer. Drug resistance in cancer chemotherapy is one of the main obstacles to curing this malignant disease. Statistical data indicate that over 90% of the mortality of patients with cancer is related to drug resistance. Drug resistance of cancer chemotherapy can be caused by many mechanisms, such as decreased antitumor drug uptake, modified drug targets, altered cell cycle checkpoints, or increased DNA damage repair, among others. In recent years, many studies have shown that miRNAs are involved in the drug resistance of tumor cells by targeting drug-resistance-related genes or influencing genes related to cell proliferation, cell cycle, and apoptosis. A single miRNA often targets a number of genes, and its regulatory effect is tissue-specific. In this review, we emphasize the miRNAs that are involved in the regulation of drug resistance among different cancers and probe the mechanisms of the deregulated expression of miRNAs. The molecular targets of miRNAs and their underlying signaling pathways are also explored comprehensively. A holistic understanding of the functions of miRNAs in drug resistance will help us develop better strategies to regulate them efficiently and will finally pave the way toward better translation of miRNAs into clinics, developing them into a promising approach in cancer therapy.

Programmable Codelivery of Doxorubicin and Apatinib Using an Implantable Hierarchical-Structured Fiber Device for Overcoming Cancer Multidrug Resistance

Multiple drug resistance (MDR) of cancer cells is a major cause of chemotherapy failure. It is currently a great challenge to develop a direct and effective strategy for continuously inhibiting the P-glycoprotein (P-gp) drug pump of MDR tumor cells, thus enhancing the intracellular concentration of the therapeutic agent for effectively killing MDR tumor cells. Here, a new implantable hierarchical-structured ultrafine fiber device is developed via a microfluidic-electrospinning technology for localized codelivery of doxorubicin (DOX) and apatinib (AP). An extremely high encapsulation efficiency of ≈99% for the dual drugs is achieved through this strategy. The release of the loaded dual drugs can be controlled in a programmable release model with a rapid release of the micelles, while AP is slowly released. The sustained release of AP can continuously inhibit the P-gp drug pump of MDR tumor cells, increasing the intracellular DOX accumulation. The in vivo DOX biodistribution displays that the DOX accumulation in the tumor tissues achieves 17.82% after implanting the fiber device for 72 h, which is 6.36-fold higher than that of the intravenously injected DOX. Importantly, the fiber device shows an excellent antitumor effect on MDR tumor-bearing mice with low systemic toxicity.

Fusobacterium nucleatum promotes chemoresistance to 5-fluorouracil by upregulation of BIRC3 expression in colorectal cancer

Background

Emerging evidence suggests a potential relationship between gut microbiota and the host response to chemotherapeutic drugs including 5-fluorouracil (5-Fu). Fusobacterium nucleatum (Fn) has been linked to the initiation and progression of colorectal cancer (CRC). Unfortunately, little was known about the relationship between Fn infection and chemotherapeutic efficacy. Here, we investigate the potential relationship between Fn infection and chemotherapeutic efficacy of 5-Fu in CRC.

Methods

Differentially expressed genes of CRC cell lines induced by Fn infection were analyzed based on a whole genome microarray analysis Then, we explored the relationship between upregulation of BIRC3 induced by Fn infection and chemoresistance to 5-Fu in vitro and in vivo. Furthermore, we dissected the mechanisms involved in Fn-induced BIRC3 expression. Finally, we investigated the clinical relevance of Fn infection, BIRC3 protein expression and chemoresistance to 5-Fu treatment in CRC patients.

Results

BIRC3 was the most upregulated gene induced by Fn infection via the TLR4/NF-κB pathway in CRC cells; Fn infection reduced the chemosensitivity of CRC cells to 5-Fu through upregulation of BIRC3 in vitro and in vivo. High Fn abundance correlated with chemoresistance in advanced CRC patients who received standard 5-Fu-based adjuvant chemotherapy after radical surgery.

Conclusions

Our evidence suggests that Fn and BIRC3 may serve as promising therapeutic targets for reducing chemoresistance to 5-Fu treatment in advanced CRC.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0985-y) contains supplementary material, which is available to authorized users.

Fragment-centric topographic mapping method guides the understanding of ABCG2-inhibitor interactions

Our study gains insight into the development of novel specific ABCG2 inhibitors, and develops a comprehensive computational strategy to understand protein ligand interaction with the help of AlphaSpace, a fragment-centric topographic mapping tool.

A new insight into the reversal of multidrug resistance in cancer by nanodrugs

This work offers novel mechanistic insights into MDR reversal by nanodrugs, and this process involves reducing the P-gp distribution ratio in the cell membrane through cellular internalization behavior rather than merely evading P-gp recognition.

Luteolin sensitizes the antitumor effect of cisplatin in drug-resistant ovarian cancer via induction of apoptosis and inhibition of cell migration and invasion

Luteolin, a polyphenolic flavone, has been demonstrated to exert anti-tumor activity in various cancer types. Cisplatin drug resistance is a major obstacle in the management of ovarian cancer. In the present study, we investigated the chemo-sensitizing effect of luteolin in both cisplatin-resistant ovarian cancer cell line and a mice xenotransplant model. In vitro, CCK-8 assay showed that luteolin inhibited cell proliferation in a dose-dependent manner, and luteolin enhanced anti-proliferation effect of cisplatin on cisplatin-resistant ovarian cancer CAOV3/DDP cells. Flow cytometry revealed that luteolin enhanced cell apoptosis in combination with cisplatin. Western blotting and qRT-PCR assay revealed that luteolin increased cisplatin-induced downregulation of Bcl-2 expression. In addition, wound-healing assay and Matrigel invasion assay showed that luteolin and cisplatin synergistically inhibited migration and invasion of CAOV3/DDP cells. Moreover, in vivo, luteolin enhanced cisplatin-induced reduction of tumor growth as well as induction of apoptosis. We suggest that luteolin in combination with cisplatin could potentially be used as a new regimen for the treatment of ovarian cancer.

Synergistic anticancer effects of timosaponin AIII and ginsenosides in MG63 human osteosarcoma cells

Background

Timosaponin AIII (TA3) is a steroidal saponin extracted from Anemarrhena asphodeloides. Here, we investigated the anticancer effects of TA3 in MG63 human osteosarcoma cells. TA3 attenuates migration and invasion of MG63 cells via regulations of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, which are involved with cancer metastasis in various cancer cells. TA3 reduced enzymatic activities and transcriptional expressions of MMP-2 and MMP-9 in MG63 cells. TA3 also inhibited Src, focal adhesion kinase, extracellular signal-regulated kinase (ERK1/2), c-Jun N-terminal kinase (JNK), p38, β-catenin, and cAMP response element binding signaling, which regulate migration and invasion of cells. TA3 induced apoptosis of MG63 cells via regulations of caspase-3, caspase-7, and poly(ADP-ribose) polymerase (PARP). Then, we tested several ginsenosides to be used in combination with TA3 for the synergistic anticancer effects. We found that ginsenosides Rb1 and Rc have synergistic effects on TA3-induced apoptosis in MG63 cells.

Methods

We investigated the anticancer effects of TA3 and synergistic effects of various ginseng saponins on TA3-induced apoptosis in MG63 cells. To test antimetastatic effects, we performed wound healing migration assay, Boyden chamber invasion assays, gelatin zymography assay, and Western blot analysis. Annexin V/PI staining apoptosis assay was performed to determine the apoptotic effect of TA3 and ginsenosides.

Results

TA3 attenuated migration and invasion of MG63 cells and induced apoptosis of MG63 cells. Ginsenosides Rb1 and Rc showed the synergistic effects on TA3-induced apoptosis in MG63 cells.

Conclusions

The results strongly suggest that the combination of TA3 and the two ginsenosides Rb1 and Rc may be a strong candidate for the effective antiosteosarcoma agent.

Reversal of Multidrug Resistance in Human Colon Cancer and Human Leukemia Cells by Three Plant Extracts and Their Major Secondary Metabolites

Background: We studied the effect of three plant extracts (Glycyrrhiza glabra, Paeonia lactiflora, Eriobotrya japonica) and six of their major secondary metabolites (glycyrrhizic acid, 18β glycyrrhetinic acid, liquiritigenin, isoliquiritigenin, paeoniflorin, ursolic acid) on the multidrug resistant human colon cancer cell line Caco-2 and human leukemia cell line CEM/ADR 5000 as compared to the corresponding sensitive cell line CCRF-CEM, and human colon cancer cells HCT-116, which do not over-express ATP-binding cassette (ABC) transporters. Methods: The cytotoxicity of single substances in sensitive and resistant cells was investigated by MTT assay. We also applied combinations of extracts or single compounds with the chemotherapeutic agent doxorubicin or doxorubicin plus the saponin digitonin. The intracellular retention of the ABC transporter substrates rhodamine 123 and calcein was examined by flow cytometry to explore the effect of the substances on the activity of ABC transporters P-glycoprotein and MRP1. Real-time PCR was applied to analyse the gene expression changes of ABCB1, ABCC1, caspase 3, caspase 8, AhR, CYP1A1, and GSTP1 in resistant cells under the treatment of the substances. Results: All the substances moderately inhibited cell growth in sensitive and resistant cells to some degree. Whereas ursolic acid showed IC50 of 14 and 22 µM in CEM/ADR 5000 and Caco-2 cells, respectively, glycyrrhizic acid and paeoniflorin were inactive with IC50 values above 400 μM. Except for liquiritigenin and isoliquiritigenin, all the other substances reversed MDR in CEM/ADR 5000 and Caco-2 cells to doxorubicin. Ue, ga, 18ga, and urs were powerful reversal agents. In CEM/ADR 5000 cells, high concentrations of all the substances, except Paeonia lactiflora extract, increased calcein or rhodamine 123 retention in a dose-dependent manner. In Caco-2 cells, all the substances, except liquiritigenin, retained rhodamine 123 in a dose-dependent manner. We also examined the effect of the plant secondary metabolite (PSM) panel on the expression of ABCB1, ABCC1, caspase 3, caspase 8, AhR, CYP1A1, and GSTP1 genes in MDR cells. Conclusions: The extracts and individual PSM could reverse MDR in CEM/ADR 5000 and Caco-2 cells, which overexpress ABC transporters, in two- and three-drug combinations. Most of the PSM also inhibited the activity of ABC transporters to some degree, albeit at high concentrations. Ue, ga, 18ga, and urs were identified as potential multidrug resistance (MDR) modulator candidates, which need to be characterized and validated in further studies.

Prophylactic intervention of probiotics (L.acidophilus, L.rhamnosus GG) and celecoxib modulate Bax-mediated apoptosis in 1,2-dimethylhydrazine-induced experimental colon carcinogenesis

BACKGROUND

Colorectal cancer has been found to be attenuated either with prophylactic manipulation of gut microbiome with probiotics or celecoxib, a non-steroidal anti-inflammatory drug mainly by suppressing early pro-carcinogenic markers in various experimental studies. Therefore, the present study was designed to assess the prophylactic potential of combinatorial administration of probiotics (Lactobacillus rhamnosus GG, Lactobacillus acidophilus) and celecoxib in experimental colon carcinogenesis.

METHODS

Six groups of Spraugue Dawely rats received probiotics L.rhamnosus GG or/and L.acidophilus in combination with celecoxib one week prior to the inducement of tumor by 1,2-dimethylhydrazine (DMH) and the treatment continued for 18 weeks. Prophylactic potentials of probiotics and celecoxib were determined by employing various methods such as tumor incidence, tumor burden, tumor multiplicity, apoptosis, caspase activity, expression of proto-oncogene K-ras and tumor suppressor p53 gene in colonic tumors.

RESULTS

Interestingly, it was found that one week prior supplementation of both probiotics and celecoxib reduced tumor burden, tumor multiplicity, down-regulated the expression of anti-apoptotic Bcl-2, proto-oncogene K-ras and up-regulated pro-apoptotic Bax as well as tumor suppressor p53 in L.rhamnosus GG + celecoxib+DMH animals compared with counter controls and DMH-treated.

CONCLUSIONS

It can be concluded that such combinatorial approach may be useful in reducing the burden and severity of disease in highly susceptible individuals but needs to be validated clinically.

Nanoparticle-Mediated Combination Therapy: Two-in-One Approach for Cancer

Cancer represents a group of heterogeneous diseases characterized by uncontrolledgrowth and spread of abnormal cells, ultimately leading to death. Nanomedicine plays a significantrole in the development of nanodrugs, nanodevices, drug delivery systems and nanocarriers. Someof the major issues in the treatment of cancer are multidrug resistance (MDR), narrow therapeuticwindow and undesired side effects of available anticancer drugs and the limitations of anticancerdrugs. Several nanosystems being utilized for detection, diagnosis and treatment such as theranosticcarriers, liposomes, carbon nanotubes, quantum dots, polymeric micelles, dendrimers and metallicnanoparticles. However, nonbiodegradable nanoparticles causes high tissue accumulation andleads to toxicity. MDR is considered a major impediment to cancer treatment due to metastatictumors that develop resistance to chemotherapy. MDR contributes to the failure of chemotherapiesin various cancers, including breast, ovarian, lung, gastrointestinal and hematological malignancies.Moreover, the therapeutic efficiency of anticancer drugs or nanoparticles (NPs) used alone is lessthan that of the combination of NPs and anticancer drugs. Combination therapy has long beenadopted as the standard first-line treatment of several malignancies to improve the clinical outcome.Combination therapy with anticancer drugs has been shown to generally induce synergistic drugactions and deter the onset of drug resistance. Therefore, this review is designed to report andanalyze the recent progress made to address combination therapy using NPs and anticancer drugs.We first provide a comprehensive overview of the angiogenesis and of the different types of NPscurrently used in treatments of cancer; those emphasized in this review are liposomes, polymericNPs, polymeric micelles (PMs), dendrimers, carbon NPs, nanodiamond (ND), fullerenes, carbonnanotubes (CNTs), graphene oxide (GO), GO nanocomposites and metallic NPs used forcombination therapy with various anticancer agents. Nanotechnology has provided the convenienttools for combination therapy. However, for clinical translation, we need continued improvementsin the field of nanotechnology.

Thiol redox-sensitive cationic polymers for dual delivery of drug and gene

Recently greater emphasis has been given to combination therapy for generating synergistic effects of treating cancer. Recent studies on thiol-sensitive nanocarriers for the delivery of drug or gene have shown promising results. In this review, we will examine the rationale and advantage in using nanocarriers for the combined delivery of different anticancer drugs and biologics. Here, we also discuss the role of nanocarriers, particularly redox-sensitive polymers in evading or inhibiting the efflux pump in cancer and how they modulate the sensitivity of cancer cells. The review aims to provide a good understanding of the new pattern of cancer treatment and key concerns for designing nanomedicine of synergistic combinations for cancer therapy.

Probing Gallate-Mediated Selectivity and High-Affinity Binding of Epigallocatechin Gallate: a Way-Forward in the Design of Selective Inhibitors for Anti-apoptotic Bcl-2 Proteins

Selective inhibition is a key focus in the design of chemotherapeutic compounds that can abrogate the oncogenic activities of anti-apoptotic Bcl-2 proteins. Although recent efforts have led to the development of highly selective BH3 mimetics, setbacks such as toxicities have limited their use in cancer therapy. Epigallocatechingallate (EGCG) has been widely reported to selectively inhibit Bcl-2 and Bcl-xL compared to other green tea phenols due to its gallate group. Herein, we investigate the interaction dynamics of EGCG at the hydrophobic grooves of Bcl-2 and Bcl-xL and the consequential effects on their BH4 domains. Arg143 and Asp108 (Bcl-2), and Glu96 and Tyr195 (Bcl-xL) formed high-affinity hydrogen interactions with the gallate group while non-gallate groups of EGCG formed weak interactions. EGCG-bound proteins showed systemic perturbations of BH4 domains coupled with the burial of crucial surface-exposed residues such as Lys17 (Bcl-2) and Asp11 (Bcl-xL); hence, a distortion of non-canonical domain interactions. Interactions of gallate group of EGCG with key hydrophobic groove residues underlie EGCG selectivity while concurrent BH4 domain perturbations potentiate EGCG inhibitory activities. Findings will aid the optimization and design of selective inhibitors that could suppress anti-apoptotic activities of Bcl2-family proteins with minimal toxicities.

Nanoformulations of doxorubicin: how far have we come and where do we go from here?

Nanotechnology, focused on discovery and development of new pharmaceutical products is known as nanopharmacology, and one research area this branch is engaged in are nanopharmaceuticals. The importance of being nano has been particularly emphasized in scientific areas dealing with nanomedicine and nanopharmaceuticals. Nanopharmaceuticals, their routes of administration, obstacles and solutions concerning their improved application and enhanced efficacy have been briefly yet comprehensively described. Cancer is one of the leading causes of death worldwide and evergrowing number of scientific research on the topic only confirms that the needs have not been completed yet and that there is a wide platform for improvement. This is undoubtedly true for nanoformulations of an anticancer drug doxorubicin, where various nanocarrriers were given an important role to reduce the drug toxicity, while the efficacy of the drug was supposed to be retained or preferably enhanced. Therefore, we present an interdisciplinary comprehensive overview of interdisciplinary nature on nanopharmaceuticals based on doxorubicin and its nanoformulations with valuable information concerning trends, obstacles and prospective of nanopharmaceuticals development, mode of activity of sole drug doxorubicin and its nanoformulations based on different nanocarriers, their brief descriptions of biological activity through assessing in vitro and in vivo behavior.

Epithelial-mesenchymal-transition-inducing transcription factors: new targets for tackling chemoresistance in cancer?

Chemoresistance remains a major complication of cancer treatments. Recent data provide strong evidence that chemoresistance is linked to epithelial-mesenchymal transition (EMT), a latent developmental process, which is re-activated during cancer progression. EMT involves transcriptional reprogramming and is driven by specific EMT transcription factors (EMT-TFs). In this review, we provide support for the idea that EMT-TFs contribute to the development of resistance against cancer therapy and discuss how EMT-TFs might be targeted to advance novel therapeutic approaches to the treatment of cancer.

In Vitro Study of Antitumor Effect of Antimicrobial Peptide Tachyplesin I in Combination with Cisplatin

We studied combined effect of β-hairpin antimicrobial peptide tachyplesin I and cytotoxic agent cisplatin on tumor and normal human cell lines. MTT assay and flow cytometry showed that tachyplesin I selectively sensitized cancer cells to cisplatin in specified concentration ratios. In vitro experiments demonstrated that combined use of tachyplesin I and cisplatin allows decreasing the effective dose of the cytostatic thus reducing nonspecific toxicity.

Nanomedicines as emerging platform for simultaneous delivery of cancer therapeutics: new developments in overcoming drug resistance and optimizing anticancer efficacy

Development and formulation of an efficient and safe therapeutic regimen for cancer theranostics are dynamically challenging. The use of mono-therapeutic cancer regimen is generally restricted to optimal clinical applications, on account of drug resistance and cancer heterogeneity. Combinatorial treatments can employ multi-therapeutics for synergistic anticancer efficacy whilst reducing the potency of individual moieties and diminishing the incidence of associated adverse effects. The combo-delivery of nanotherapeutics can optimize anti-tumor efficacy while reversing the incidence of drug resistance, aiming to homogenize pharmacological profile of drugs, enhance circulatory time, permit targeted drug accumulation, achieve multi-target dynamic approach, optimize target-specific drug binding and ensure sustained drug release at the target site. Numerous nanomedicines/nanotherapeutics have been developed by having dynamic physicochemical, pharmaceutical and pharmacological implications. These innovative delivery approaches have displayed specialized treatment effects, alone or in combination with conventional anticancer approaches (photodynamic therapy, radiotherapy and gene therapy), while reversing drug resistance and potential off-target effects. The current review presents a comprehensive overview of nanocarrier aided multi-drug therapies alongside recent advancements, future prospects, and the pivotal requirements for interdisciplinary research.