Molecular mechanisms of drug resistance and its reversal in cancer

Mobocertinib antagonizes multidrug resistance in ABCB1- and ABCG2-overexpressing cancer cells: in vitro and in vivo studies

Overexpression of ATP-binding cassette (ABC) transporters, particularly ABCB1 and ABCG2, strongly correlates with multidrug resistance (MDR), rendering cancer chemotherapy ineffective. Exploration and identification of novel inhibitors targeting ABCB1 and ABCG2 are necessary to overcome the related MDR. Mobocertinib is an approved EGFR/HER2 inhibitor for non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion mutations. This study demonstrates that mobocertinib can potentially reverse ABCB1- and ABCG2-mediated MDR. Our findings indicate a strong interaction between mobocertinib and these two proteins, supported by its high binding affinity with ABCB1 and ABCG2 models. Through inhibiting the drug efflux function of ABCB1 and ABCG2, mobocertinib facilitates substrate drugs accumulation, thereby re-sensitizing substrate drugs in drug-resistant cancer cells. Additionally, mobocertinib inhibited the ATPase activity of ABCB1 and ABCG2 without changing the expression levels or subcellular localization. In the tumor-bearing mouse model, mobocertinib boosted the antitumor effect of paclitaxel and topotecan, resulting in tumor regression. In summary, our study uncovers a novel potential for repurposing mobocertinib as a dual inhibitor of ABCB1 and ABCG2, and suggests the combination of mobocertinib with substrate drugs as a strategy to counteract MDR.

A Specific Targeted Enhanced Nanotherapy Strategy for Inducing Ferroptosis by Regulating the Iron Pool Levels in Tumor Cells

Ferroptosis is an iron-dependent cell death pathway triggered by the toxic accumulation of lipid peroxides on cellular membranes. However, an imbalance in iron metabolism in tumor cells leads to the insufficient accumulation of iron ions in the iron pool, which inhibits ferroptosis. Nonspecific delivery of iron species may increase the risk of promoting tumor proliferation as well as trigger undesirable detrimental effects such as anaphylactic reactions in normal tissues. This study found that a constructed self-enhancing targeted nanocarrier can accurately regulate the iron pool levels in tumor cells. We constructed a programmatic targeted enhanced nanotherapy strategy by loading the ferroptosis inducer erastin into a self-enhancing targeted nanocarrier. This nanosystem was more effective at inducing tumor ferroptosis after upregulating the iron pool levels in tumor cells with self-enhancing targeted nanocarriers. Both in vitro and in vivo outcomes demonstrated notable anticancer ferroptosis efficacy, indicating that self-enhancing targeted nanocarriers can effectively regulate the level of the iron pool in tumor cells and promote ferroptosis. The combination of this nanotherapy strategy with self-enhancing targeted chemotherapy nanomedicines can achieve complete tumor clearance. Moreover, this self-enhancing targeted ferroptosis nanotherapy strategy is expected to be beneficial for future progress in the field of cancer self-enhancing targeted therapy.

Inhibition of EREG/ErbB/ERK by Astragaloside IV reversed taxol-resistance of non-small cell lung cancer through attenuation of stemness via TGFβ and Hedgehog signal pathway

PURPOSE

Taxol is the first-line chemo-drug for advanced non-small cell lung cancer (NSCLC), but it frequently causes acquired resistance, which leads to the failure of treatment. Therefore, it is critical to screen and characterize the mechanism of the taxol-resistance reversal agent that could re-sensitize the resistant cancer cells to chemo-drug.

METHOD

The cell viability, sphere-forming and xenografts assay were used to evaluate the ability of ASIV to reverse taxol-resistance. Immunohistochemistry, cytokine application, small-interfering RNA, small molecule inhibitors, and RNA-seq approaches were applied to characterize the molecular mechanism of inhibition of epiregulin (EREG) and downstream signaling by ASIV to reverse taxol-resistance.

RESULTS

ASIV reversed taxol resistance through suppression of the stemness-associated genes of spheres in NSCLC. The mechanism exploration revealed that ASIV promoted the K48-linked polyubiquitination of EREG along with degradation. Moreover, EREG could be triggered by chemo-drug treatment. Consequently, EREG bound to the ErbB receptor and activated the ERK signal to regulate the expression of the stemness-associated genes. Inhibition of EREG/ErbB/ERK could reverse the taxol-resistance by inhibiting the stemness-associated genes. Finally, it was observed that TGFβ and Hedgehog signaling were downstream of EREG/ErbB/ERK, which could be targeted using inhibitors to reverse the taxol resistance of NSCLC.

CONCLUSIONS

These findings revealed that inhibition of EREG by ASIV reversed taxol-resistance through suppression of the stemness of NSCLC via EREG/ErbB/ERK-TGFβ, Hedgehog axis.

Resveratrol: biology, metabolism, and detrimental role on the tumor microenvironment of colorectal cancer

A substantial increase in colorectal cancer (CRC)-associated fatalities can be attributed to tumor recurrence and multidrug resistance. Traditional treatment options, including radio- and chemotherapy, also exhibit adverse side effects. Ancient treatment strategies that include phytochemicals like resveratrol are now widely encouraged as an alternative therapeutic option. Resveratrol is the natural polyphenolic stilbene in vegetables and fruits like grapes and apples. It inhibits CRC progression via targeting dysregulated cancer-promoting pathways, including PI3K/Akt/Kras, targeting transcription factors like NF-κB and STAT3, and an immunosuppressive tumor microenvironment. In addition, combination therapies for cancer include resveratrol as an adjuvant to decrease multidrug resistance that develops in CRC cells. The current review discusses the biology of resveratrol and explores different mechanisms of action of resveratrol in inhibiting CRC progression. Further, the detrimental role of resveratrol on the immunosuppressive tumor microenvironment of CRC has been discussed. This review illustrates clinical trials on resveratrol in different cancers, including resveratrol analogs, and their efficiency in promoting CRC inhibition.

Marein, a novel natural product for restoring chemo-sensitivity to cancer cells through competitive inhibition of ABCG2 function

The pivotal roles of ATP-binding cassette (ABC) transporters in drug resistance have been widely appreciated. Here we report that marein, a natural product from Coreopsis tinctoria Nutt, is a potent chemo-sensitizer in drug resistant cancer cells overexpressing ABCG2 transporter. We demonstrate that marein can competitively inhibit efflux activity of ABCG2 protein and increase the intracellular accumulation of the chemotherapeutic drugs that belong to substrate of this transporter. We further show that marein can bind to the conserved amino acid residue F439 of ABCG2, a critical site for drug-substrate interaction. Moreover, marein can significantly sensitize the ABCG2-expressing tumor cells to chemotherapeutic drugs such as topotecan, mitoxantrone, and olaparib. This study reveals a novel role and mechanism of marein in modulating drug resistance, and may have important implications in treatment of cancers that are resistant to chemotherapeutic drugs that belong to the substrates of ABCG2 transporters.

Role of the RNA binding protein IGF2BP1 in cancer multidrug resistance

The insulin-like growth factor-2 mRNA-binding protein 1 (IGF2BP1), a member of a conserved family of single-stranded RNA-binding proteins (IGF2BP1-3), is expressed in a broad range of fetal tissues, placenta and more than sixteen cancer types but only in a limited number of normal adult tissues. IGF2BP1is required for the transport from nucleus to cytoplasm of certain mRNAs that play essential roles in embryogenesis, carcinogenesis, and multidrug resistance (MDR), by affecting their stability, translation, or localization. The purpose of this review is to gather and present information on MDR mechanisms in cancer and the significance of IGF2BP1 in this context. Within this review, we will provide an overview of IGF2BP1, including its tissue distribution, expression, molecular targets in the context of tumorigenesis and its inhibitors. Our main focus will be on elucidating the interplay between IGF2BP1 and MDR, particularly with regard to chemoresistance mediated by ABC transporters.

The Drug Transporter P-Glycoprotein and Its Impact on Ceramide Metabolism-An Unconventional Ally in Cancer Treatment

The tumor-suppressor sphingolipid ceramide is recognized as a key participant in the cytotoxic mechanism of action of many types of chemotherapy drugs, including anthracyclines, Vinca alkaloids, the podophyllotoxin etoposide, taxanes, and the platinum drug oxaliplatin. These drugs can activate de novo synthesis of ceramide or stimulate the production of ceramide via sphingomyelinases to limit cancer cell survival. On the contrary, dysfunctional sphingolipid metabolism, a prominent factor in cancer survival and therapy resistance, blunts the anticancer properties of ceramide-orchestrated cell death pathways, especially apoptosis. Although P-glycoprotein (P-gp) is famous for its role in chemotherapy resistance, herein, we propose alternate interpretations and discuss the capacity of this multidrug transporter as a "ceramide neutralizer", an unwelcome event, highlighting yet another facet of P-gp's versatility in drug resistance. We introduce sphingolipid metabolism and its dysfunctional regulation in cancer, present a summary of factors that contribute to chemotherapy resistance, explain how P-gp "neutralizes" ceramide by hastening its glycosylation, and consider therapeutic applications of the P-gp-ceramide connection in the treatment of cancer.

Unique Advantages of Dendrimers-Structured Mesoporous Silica Nanoparticles over Traditional Hollow Ones in Delivering Bcl2-Functional Converting Peptide for Multidrug Resistant Cancer Treatment

Innovative silica nanomaterials have made the significant advancements in curative therapy against cancers with multidrug resistance (MDR). The study on different-nanostructured mesoporous silica nanoparticles (MSNs) with discrepant pore sizes affecting biomacromolecules in resisting cancer MDR hasn't been reported yet. In this study, a systematic comparison of 6 nm-pore sized hollow-structured MSNs (HMSNs) and 10 nm-pore sized dendrimers-structured MSNs (LMSNs) for delivering Bcl-2-functional converting peptide (N9) or doxorubicin (DOX) to overcome cancer MDR is comprehensively carried out both in in vitro and in vivo resistant tumor models. The results show that both LMSNs and HMSNs exert no significant difference in delivering DOX to treat drug-resistant cancers. However, compared with N9@HMSNs, N9@LMSNs display the increased loading efficiency, the improved cell-penetrative capability, the higher cancer cell apoptosis effect, the enhanced tumor accumulation and retention efficiency, and the final elevated tumor inhibition efficiency. Unexpectedly, naked LMSNs without surface modification especially at high dosage produce relatively more serious toxicity than HMSNs whatever in cells, zebrafish embryo or mice models. Collectively, the data provide the sufficient theoretical evidence that LMSNs might be a better choice for delivering biomacromolecules to treat resistant cancers after appropriate surface functionalization such as with PEGylation to weaken its intrinsic toxicity.

Deformable Smart DNA Nanomachine for Synergistic Intracellular Cancer-Related miRNAs Imaging and Chemo-Gene Therapy of Drug-Resistant Tumors

Diagnosis and treatment of tumor especially drug-resistant tumor remains a huge challenge, which requires intelligent nanomedicines with low toxic side effects and high efficacy. Herein, deformable smart DNA nanomachines are developed for synergistic intracellular cancer-related miRNAs imaging and chemo-gene therapy of drug-resistant tumors. The tetrahedral DNA framework (MA-TDNA) with fluorescence quenched component and five antennas is self-assembled first, and then DOX molecules are loaded on the MA-TDNAs followed by linking MUC1-aptamer and Mcl-1 siRNA to the antennas of MA-TDNA, so that the apt-MA-TDNA@DOX-siRNA (DNA nanomachines) is constructed. The DNA nanomachine can respond to two tumor-related miRNAs in vitro and in vivo, which can undergo intelligent miRNA-triggered opening of the framework, resulting in the "turn on" of the fluorescence for sensitively and specifically sensing intracellular miRNAs. Meanwhile, both miRNA-responded rapid release and pH-responded release of DOX are achieved for chemotherapy of tumor. In addition, the gene therapy of the DNA nanomachines is achieved due to the miRNA-specific capture and the RNase H triggered release of Mcl-1 siRNA. The DNA nanomachines intergrading both tumor imaging and chemo-gene therapy in single nanostructures realized efficient tumor-targeted, image-guided, and microenvironment-responsive tumor diagnosis and treatment, which provides a synergetic antitumor effect on drug-resistant tumor.

CircRNAs in cancer therapy tolerance

The rapidly expanding field of circular RNA (circ-RNA) research has opened new avenues in cancer diagnostics and treatment, highlighting the role of serum circRNAs as potential biomarkers for assessing tumor therapy resistance. This review comprehensively compiles existing knowledge regarding the biogenesis, function, and clinical relevance of circRNAs, emphasizing their stability, abundance, and cell type-specific expression profiles, which make them ideal candidates for noninvasive early biomarkers in cancer treatment. We explored the roles of circRNAs in oncogenesis and tumor progression and their complex interactions with patient responses to various cancer treatments, such as chemotherapy, radiotherapy, targeted therapy, and immunotherapy. Through the analysis of data from recent studies and clinical trials, we underscore the prognostic significance of serum circRNAs in predicting therapeutic outcomes, their involvement in resistance mechanisms, and their capacity to inform personalized treatment approaches. Additionally, this review addresses the obstacles inherent in circRNA research, including the need for standardized protocols for circRNA extraction and quantification and the elucidation of the clinical significance of circRNAs. Furthermore, our investigation extends to future prospects, including embedding circRNA profiling into regular clinical workflows and pioneering circRNA-based therapeutic approaches. We underscore the transformative potential of serum circRNAs in enhancing cancer diagnosis, improving the accuracy of therapy tolerance predictions, and ultimately fostering the advent of precision oncology.

SOAT1 regulates cholesterol metabolism to induce EMT in hepatocellular carcinoma

Cholesterol metabolism reprogramming is one of the significant characteristics of hepatocellular carcinoma (HCC). Cholesterol increases the risk of epithelial-mesenchymal transition (EMT) in cancer. Sterol O-acyltransferases 1 (SOAT1) maintains the cholesterol homeostasis. However, the exact mechanistic contribution of SOAT1 to EMT in HCC remains unclear. Here we demonstrated that SOAT1 positively related to poor prognosis of HCC, EMT markers and promoted cell migration and invasion in vitro, which was mediated by the increased cholesterol in plasmalemma and cholesterol esters accumulation. Furthermore, we reported that SOAT1 disrupted cholesterol metabolism homeostasis to accelerate tumorigenesis and development in HCC xenograft and NAFLD-HCC. Also, we detected that nootkatone, a sesquiterpene ketone, inhibited EMT by targeting SOAT1 in vitro and in vivo. Collectively, our finding indicated that SOAT1 promotes EMT and contributes to hepatocarcinogenesis by increasing cholesterol esterification, which is suppressed efficiently by nootkatone. This study demonstrated that SOAT1 is a potential biomarker and therapeutic target in NAFLD-HCC and SOAT1-targeting inhibitors are expected to be the potential new therapeutic treatment for HCC.

Efficacy and safety of Trastuzumab Emtansine in treating human epidermal growth factor receptor 2-positive metastatic breast cancer in Chinese population: a real-world multicenter study

Background

Trastuzumab emtansine (T-DM1) has been approved worldwide for treating metastatic breast cancer (mBC) in patients who have received first-line therapy, shown disease progression, and are human epidermal growth factor receptor 2 (HER2)-positive. T-DM1 received approval in China to treat early-stage breast cancer (BC) in 2020 and for mBC in 2021. In March 2023, T-DM1 was included in medical insurance coverage, significantly expanding the eligible population.

Materials and methods

This post-marketing observational study aimed to assess the safety and effectiveness of T-DM1 in real-world clinical practice in China. This study enrolled 31 individuals with HER2-positive early-stage BC and 70 individuals with HER2-positive advanced BC from 8 study centers in Shandong Province, China. The T-DM1 dosage was 3.6 mg/kg injected intravenously every 3 weeks until the disease advanced or the drug toxicity became uncontrollable, whichever occurred earlier. Additionally, efficacy and safety information on T-DM1 were collected.

Results

During the 7-month follow-up period, no recurrence or metastases were observed in patients who had early-stage BC. The disease control rate was 31.43% (22/70) in patients with advanced BC. The most common adverse effect of T-DM1 was thrombocytopenia, with an incidence of 69.31% (70/101), and the probability of Grade ≥ 3 thrombocytopenia was 11.88% (12/101).

Conclusion

This real-world study demonstrated that T-DM1 had good efficacy and was well tolerated by both HER2-positive early-stage BC and mBC patients.

Nanozymes with biomimetically designed properties for cancer treatment

Nanozymes, as a type of nanomaterials with enzymatic catalytic activity, have demonstrated tremendous potential in cancer treatment owing to their unique biomedical properties. However, the heterogeneity of tumors and the complex tumor microenvironment pose significant challenges to the in vivo catalytic efficacy of traditional nanozymes. Drawing inspiration from natural enzymes, scientists are now using biomimetic design to build nanozymes from the ground up. This approach aims to replicate the key characteristics of natural enzymes, including active structures, catalytic processes, and the ability to adapt to the tumor environment. This achieves selective optimization of nanozyme catalytic performance and therapeutic effects. This review takes a deep dive into the use of these biomimetically designed nanozymes in cancer treatment. It explores a range of biomimetic design strategies, from structural and process mimicry to advanced functional biomimicry. A significant focus is on tweaking the nanozyme structures to boost their catalytic performance, integrating them into complex enzyme networks similar to those in biological systems, and adjusting functions like altering tumor metabolism, reshaping the tumor environment, and enhancing drug delivery. The review also covers the applications of specially designed nanozymes in pan-cancer treatment, from catalytic therapy to improved traditional methods like chemotherapy, radiotherapy, and sonodynamic therapy, specifically analyzing the anti-tumor mechanisms of different therapeutic combination systems. Through rational design, these biomimetically designed nanozymes not only deepen the understanding of the regulatory mechanisms of nanozyme structure and performance but also adapt profoundly to tumor physiology, optimizing therapeutic effects and paving new pathways for innovative cancer treatment.

Nitrogen-containing andrographolide derivatives with multidrug resistance reversal effects in cancer cells

Multidrug resistance (MDR) remains a challenging issue in cancer treatment. Aiming at finding anticancer agents to overcome MDR, the triacetyl derivative (2) of the labdane diterpenoid lactone andrographolide (1) underwent the Michael-type addition reaction followed by elimination, yielding twenty-three new derivatives, bearing nitrogen-containing substituents (3-25). Their structures were assigned, mainly, by 1D and 2D NMR experiments. The MDR reversal potential of compounds 1-25 was assessed, by functional and chemosensitivity assays, using resistant human ABCB1-gene transfected L5178Y mouse lymphoma cells as a model. Several derivatives exhibited remarkable P-glycoprotein (P-gp) inhibitory ability. Compounds 13 and 20, bearing thiosemicarbazide moieties, were the most active exhibiting a strong MDR reversal effect at 2 μM. Some compounds showed selectivity towards the resistant cells, with compound 5 exhibiting a collateral sensitivity effect associated with significant antiproliferative activity (IC50 = 5.47 ± 0.22 μM). Moreover, all selected compounds displayed synergistic interaction with doxorubicin, with compound 3 being the most active. In the ATPase assay, selected compounds exhibited characteristics of P-gp inhibitors.

Cellular and molecular mechanisms of oroxylin A in cancer therapy: Recent advances

Seeking an effective and safe scheme is the common goal of clinical treatment of tumor patients. In recent years, traditional Chinese medicine has attracted more and more attention in order to discover new drugs with good anti-tumor effects. Oroxylin A (OA) is a compound found in natural Oroxylum indicum and Scutellaria baicalensis Georgi plants and has been used in the treatment of various cancers. Studies have shown that OA has a wide range of powerful biological activities and plays an important role in neuroprotection, anti-inflammation, anti-virus, anti-allergy, anti-tumor and so on. OA shows high efficacy in tumor treatment. Therefore, it has attracted great attention of researchers all over the world. This review aims to discuss the anti-tumor effects of OA from the aspects of cell cycle arrest, induction of cell proliferation and apoptosis, induction of autophagy, anti-inflammation, inhibition of glycolysis, angiogenesis, invasion, metastasis and reversal of drug resistance. In addition, the safety and toxicity of the compound were also discussed. As a next step, to clarify the benefits and adverse effects of Oroxylin A in cancer patients further experiments, especially clinical trials, are needed.

Phenylspirodrimane with Moderate Reversal Effect of Multidrug Resistance Isolated from the Deep-Sea Fungus Stachybotrys sp. 3A00409

Two new phenylspirodrimanes, stachybotrins K and L (1 and 2), together with eight known analogues (3-10), were isolated from deep-sea-derived Stachybotrys sp. MCCC 3A00409. Their structures were determined by extensive NMR data and mass spectroscopic analysis. Absolute configurations of new compounds were determined through a comparison of their circular dichroism (CD) spectra with other reported compounds. The possible reversal effects of all compounds were assayed in the resistant cancer cell lines. Stachybotrysin B (8) can reverse multidrug resistance (MDR) in ABCB1-overexpression cells (KBv200, Hela/VCR) at the non-cytotoxic concentration. Doxorubicin accumulation assay and molecular-docking analysis reveal that the mechanism of its reversal MDR effect may be related to the increase in the intracellular concentration of substrate anticancer drugs.

Long noncoding RNAs and their possible roles in tumorigenesis and drug resistance in cancer chemotherapy

Cancer is still one of the most important diseases that have a high mortality rate around the world. The management of cancer involves many procedures, which include surgery, radiotherapy, and chemotherapy. Drug resistance in cancer chemotherapy is considered one of the most important problems in clinical oncology. A good understanding of the tumorigenesis process and the mechanisms of developing chemotherapy resistance in cancer cells will help achieve significant advances in cancer treatment protocols. In recent years, there has been an increasing interest in long noncoding RNAs (lncRNAs). LncRNAs are no longer just a transcriptional noise, and many investigations proved their possible roles in regulating mandatory cellular functions. A lot of newly published studies confirmed the implication of lncRNAs in the tumor formation process and the multiple drug resistance in cancer chemotherapy. The main aim of this review is to focus on the lncRNAs' functions in the cell, their possible roles in the tumor formation process, and their roles in the development of chemotherapy resistance in different cancer cells.

Effect of Hydrogel Stiffness on Chemoresistance of Breast Cancer Cells in 3D Culture

Chemotherapy is one of the most common strategies for cancer treatment, whereas drug resistance reduces the efficiency of chemotherapy and leads to treatment failure. The mechanism of emerging chemoresistance is complex and the effect of extracellular matrix (ECM) surrounding cells may contribute to drug resistance. Although it is well known that ECM plays an important role in orchestrating cell functions, it remains exclusive how ECM stiffness affects drug resistance. In this study, we prepared agarose hydrogels of different stiffnesses to investigate the effect of hydrogel stiffness on the chemoresistance of breast cancer cells to doxorubicin (DOX). Agarose hydrogels with a stiffness range of 1.5 kPa to 112.3 kPa were prepared and used to encapsulate breast cancer cells for a three-dimensional culture with different concentrations of DOX. The viability of the cells cultured in the hydrogels was dependent on both DOX concentration and hydrogel stiffness. Cell viability decreased with DOX concentration when the cells were cultured in the same stiffness hydrogels. When DOX concentration was the same, breast cancer cells showed higher viability in high-stiffness hydrogels than they did in low-stiffness hydrogels. Furthermore, the expression of P-glycoprotein mRNA in high-stiffness hydrogels was higher than that in low-stiffness hydrogels. The results suggested that hydrogel stiffness could affect the resistance of breast cancer cells to DOX by regulating the expression of chemoresistance-related genes.

EGR1 mediates MDR1 transcriptional activity regulating gemcitabine resistance in pancreatic cancer

BACKGROUND

Gemcitabine is a cornerstone drug for the treatment of all stages of pancreatic cancer and can prolong the survival of patients with pancreatic cancer, but resistance to gemcitabine in pancreatic cancer patients hinders its efficacy. The overexpression of Early growth response 1(EGR1) in pancreatic ductal adenocarcinoma as a mechanism of gemcitabine chemoresistance in pancreatic cancer has not been explored. The major mechanisms of gemcitabine chemoresistance are related to drug uptake, metabolism, and action. One of the common causes of tumor multidrug resistance (MDR) to chemotherapy in cancer cells is that transporter proteins increase intracellular drug efflux and decrease drug concentrations by inducing anti-apoptotic mechanisms. It has been reported that gemcitabine binds to MDR1 with high affinity. The purpose of this research was to investigate the potential mechanisms by which EGR1 associates with MDR1 to regulate gemcitabine resistance in pancreatic cancer cells.

METHODS

The following in vitro and in vivo techniques were used in this research to explore the potential mechanisms by which EGR1 binds to MDR1 to regulate gemcitabine resistance in pancreatic cancer cells. Cell culture; in vitro and in vivo study of EGR1 function by loss of function analysis. Binding of EGR1 to the MDR1 promoter was detected using the ChIP assay. qRT-PCR, Western blot assays to detect protein and mRNA expression; use of Annexin V apoptosis detection assay to test apoptosis; CCK8, Edu assay to test cell proliferation viability. The animal model of pancreatic cancer subcutaneous allograft was constructed and the tumours were stained with hematoxylin eosin and Ki-67 expression was detected using immunohistochemistry.

FINDINGS

We revealed that EGR1 expression was increased in different pancreatic cancer cell lines compared to normal pancreatic ductal epithelial cells. Moreover, gemcitabine treatment induced upregulation of EGR1 expression in a dose- and time-dependent manner. EGR1 is significantly enriched in the MDR1 promoter sequence.Upon knockdown of EGR1, cell proliferation was impaired in CFPAC-1 and PANC-1 cell lines, apoptosis was enhanced and MDR1 expression was decreased, thereby partially reversing gemcitabine chemoresistance. In animal experiments, knockdown of EGR1 enhanced the inhibitory effect of gemcitabine on tumor growth compared with the sh-NC group.

CONCLUSIONS

Our study suggests that EGR1 may be involved in the regulation of MDR1 to enhance gemcitabine resistance in pancreatic cancer cells. EGR1 could be a novel therapeutic target to overcome gemcitabine resistance in pancreatic cancer.

Establishment of skin cutaneous melanoma prognosis model based on vascular mimicry risk score

Studies have indicated that Vascular mimicry (VM) could contribute to the unfavorable prognosis of skin cutaneous melanoma (SKCM). Thus, the objective of this study was to identify therapeutic targets associated with VM in SKCM and develop a novel prognostic model. Gene expression data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) were utilized to identify differentially expressed genes (DEGs). By intersecting these DEGs with VM genes, we acquired VM-related DEGs specific to SKCM, and then identified prognostic-related VM genes. A VM risk score system was established based on these prognosis-associated VM genes, and patients were then categorized into high- and low-score groups using the median score. Subsequently, differences in clinical characteristics, gene set enrichment analysis (GSEA), and other analyses were further presented between the 2 groups of patients. Finally, a novel prognostic model for SKCM was established using the VM score and clinical characteristics. 26 VM-related DEGs were identified in SKCM, among the identified DEGs associated with VM in SKCM, 5 genes were found to be prognostic-related. The VM risk score system, comprised of these genes, is an independent prognostic risk factor. There were significant differences between the 2 patient groups in terms of age, pathological stage, and T stage. VM risk scores are associated with epithelial biological processes, angiogenesis, regulation of the SKCM immune microenvironment, and sensitivity to targeted drugs. The novel prognostic model demonstrates excellent predictive ability. Our study identified VM-related prognostic markers and therapeutic targets for SKCM, providing novel insights for clinical diagnosis and treatment.

Overcoming Chemotherapy Resistance in Metastatic Cancer: A Comprehensive Review

The management of metastatic cancer is complicated by chemotherapy resistance. This manuscript provides a comprehensive academic review of strategies to overcome chemotherapy resistance in metastatic cancer. The manuscript presents background information on chemotherapy resistance in metastatic cancer cells, highlighting its clinical significance and the current challenges associated with using chemotherapy to treat metastatic cancer. The manuscript delves into the molecular mechanisms underlying chemotherapy resistance in subsequent sections. It discusses the genetic alterations, mutations, and epigenetic modifications that contribute to the development of resistance. Additionally, the role of altered drug metabolism and efflux mechanisms, as well as the activation of survival pathways and evasion of cell death, are explored in detail. The strategies to overcome chemotherapy resistance are thoroughly examined, covering various approaches that have shown promise. These include combination therapy approaches, targeted therapies, immunotherapeutic strategies, and the repurposing of existing drugs. Each strategy is discussed in terms of its rationale and potential effectiveness. Strategies for early detection and monitoring of chemotherapy drug resistance, rational drug design vis-a-vis personalized medicine approaches, the role of predictive biomarkers in guiding treatment decisions, and the importance of lifestyle modifications and supportive therapies in improving treatment outcomes are discussed. Lastly, the manuscript outlines the clinical implications of the discussed strategies. It provides insights into ongoing clinical trials and emerging therapies that address chemotherapy resistance in metastatic cancer cells. The manuscript also explores the challenges and opportunities in translating laboratory findings into clinical practice and identifies potential future directions and novel therapeutic avenues. This comprehensive review provides a detailed analysis of strategies to overcome chemotherapy resistance in metastatic cancer. It emphasizes the importance of understanding the molecular mechanisms underlying resistance and presents a range of approaches for addressing this critical issue in treating metastatic cancer.

Activation of the TGF-β1/EMT signaling pathway by claudin-1 overexpression reduces doxorubicin sensitivity in small cell lung cancer SBC-3 cells

Small-cell lung cancer (SCLC), which accounts for about 15 % of all lung cancers, progresses more rapidly than other histologic types and is rarely detected at an operable early stage. Therefore, chemotherapy, radiation therapy, or their combination are the primary treatments for this type of lung cancer. However, the tendency to acquire resistance to anticancer drugs is a severe problem. Recently, we found that an intercellular adhesion molecule, claudin (CLDN) 1, known to be involved in the migration and invasion of lung cancer cells, is involved in the acquisition of anticancer drug resistance. In the present study, we investigated the effect of CLDN1 on the anticancer-drug sensitivity of SCLC SBC-3 cells. Since epithelial-mesenchymal transition (EMT), which is involved in cancer cell migration and invasion, is well known for its involvement in anticancer-drug sensitivity via inhibition of apoptosis, we also examined EMT involvement in decreased anticancer-drug sensitivity by CLDN1. Sensitivity to doxorubicin (DOX) in SBC-3 cells was significantly decreased by CLDN1 overexpression. CLDN1 overexpression resulted in increased TGF-β1 levels, enhanced EMT induction, and increased migratory potency of SBC-3 cells. The decreased sensitivity of SBC-3 cells to anticancer drugs upon TGF-β1 treatment suggested that activation of the TGF-β1/EMT signaling pathway by CLDN1 causes the decreased sensitivity to anticancer drugs and increased migratory potency. Furthermore, treatments with antiallergic agents tranilast and zoledronic acid, known EMT inhibitors, significantly mitigated the decreased sensitivity of CLDN1-overexpressing SBC-3 cells to DOX. These results suggest that EMT inhibitors might effectively overcome reduced sensitivity to anticancer drugs in CLDN1-overexpressing SCLC cells.

Peptide-Hydrogel Nanocomposites for Anti-Cancer Drug Delivery

Cancer is the second leading cause of death globally, but conventional anticancer drugs have side effects, mainly due to their non-specific distribution in the body in both cancerous and healthy cells. To address this relevant issue and improve the efficiency of anticancer drugs, increasing attention is being devoted to hydrogel drug-delivery systems for different kinds of cancer treatment due to their high biocompatibility and stability, low side effects, and ease of modifications. To improve the therapeutic efficiency and provide multi-functionality, different types of nanoparticles (NPs) can be incorporated within the hydrogels to form smart hydrogel nanocomposites, benefiting the advantages of both counterparts and suitable for advanced anticancer applications. Despite many papers on non-peptide hydrogel nanocomposites, there is limited knowledge about peptide-based nanocomposites, specifically in anti-cancer drug delivery. The aim of this short but comprehensive review is, therefore, to focus attention on the synergies resulting from the combination of NPs with peptide-based hydrogels. This review, which includes a survey of recent advances in this kind of material, does not aim to be an exhaustive review of hydrogel technology, but it instead highlights recent noteworthy publications and discusses novel perspectives to provide valuable insights into the promising synergic combination of peptide hydrogels and NPs for the design of novel anticancer drug delivery systems.

Cell Membrane Sialome: Sialic Acids as Therapeutic Targets and Regulators of Drug Resistance in Human Cancer Management

A cellular sialome is a physiologically active and dynamically changing component of the cell membrane. Sialylation plays a crucial role in tumor progression, and alterations in cellular sialylation patterns have been described as modulators of chemotherapy effectiveness. However, the precise mechanisms through which altered sialylation contributes to drug resistance in cancer are not yet fully understood. This review focuses on the intricate interplay between sialylation and cancer treatment. It presents the role of sialic acids in modulating cell-cell interactions, the extracellular matrix (ECM), and the immunosuppressive processes within the context of cancer. The issue of drug resistance is also discussed, and the mechanisms that involve transporters, the tumor microenvironment, and metabolism are analyzed. The review explores drugs and therapeutic approaches that may induce modifications in sialylation processes with a primary focus on their impact on sialyltransferases or sialidases. Despite advancements in cellular glycobiology and glycoengineering, an interdisciplinary effort is required to decipher and comprehend the biological characteristics and consequences of altered sialylation. Additionally, understanding the modulatory role of sialoglycans in drug sensitivity is crucial to applying this knowledge in clinical practice for the benefit of cancer patients.

Nanotechnology-empowered strategies in treatment of skin cancer

In current scenario skin cancer is a serious condition that has a significant impact on world health. Skin cancer is divided into two categories: melanoma skin cancer (MSC) and non-melanoma skin cancer (NMSC). Because of its significant psychosocial effects and need for significant investment in new technology and therapies, skin cancer is an illness of global health relevance. From the patient's perspective chemotherapy considered to be the most acceptable form of treatment. However, significant negatives of chemotherapy such as severe toxicities and drug resistance pose serious challenges to the treatment. The field of nanomedicine holds significant promise for enhancing the specificity of targeting neoplastic cells through the facilitation of targeted drug delivery to tumour cells. The integration of multiple therapeutic modalities to selectively address cancer-promoting or cell-maintaining pathways constitutes a fundamental aspect of cancer treatment. The use of mono-therapy remains prevalent in the treatment of various types of cancer, it is widely acknowledged in the academic community that this conventional approach is generally considered to be less efficacious compared to the combination treatment strategy. The employment of combination therapy in cancer treatment has become increasingly widespread due to its ability to produce synergistic anticancer effects, mitigate toxicity associated with drugs, and inhibit multi-drug resistance by means of diverse mechanisms. Nanotechnology based combination therapy represents a promising avenue for the development of efficacious therapies for skin cancer within the context of this endeavour. The objective of this article is to provide a description of distinct challenges for efficient delivery of drugs via skin. This article also provides a summary of the various nanotechnology based combinatorial therapy available for skin cancer with their recent advances. This review also focuses on current status of clinical trials of such therapies.

The Application of Nano-drug Delivery System With Sequential Drug Release Strategies in Cancer Therapy

Currently, multidrug combinations are often used clinically to improve the efficacy of oncology chemotherapy, but multidrug combinations often lead to multidrug resistance and decreased performance, resulting in more severe side effects than monotherapy. Therefore, sequential drug release strategies in time and space as well as nano-carriers that respond to the tumor microenvironment have been developed. First, the advantage of the sequential release strategy is that they can load multiple drugs simultaneously to meet their spatiotemporal requirements and stability, thus exerting synergistic effects of two or more drugs. Second, in some cases, sequential drug delivery of different molecular targets can improve the sensitivity of cancer cells to drugs. Control the metabolism of cancer cells, and remodel tumor vasculature. Finally, some drug combinations with built-in release control are used for sequential administration. This paper focuses on the use of nanotechnology and built-in control device to construct drug delivery carriers with different stimulation responses, thus achieving the sequential release of drugs. Therefore, the nano-sequential delivery carrier provides a new idea and platform for the therapeutic effect of various drugs and the synergistic effect among drugs.

Repositioning of HMG-CoA Reductase Inhibitors as Adjuvants in the Modulation of Efflux Pump-Mediated Bacterial and Tumor Resistance

Efflux pump (EP)-mediated multidrug resistance (MDR) seems ubiquitous in bacterial infections and neoplastic diseases. The diversity and lack of specificity of these efflux mechanisms raise a great obstacle in developing drugs that modulate efflux pumps. Since developing novel chemotherapeutic drugs requires large investments, drug repurposing offers a new approach that can provide alternatives as adjuvants in treating resistant microbial infections and progressive cancerous diseases. Hydroxy-methyl-glutaryl coenzyme-A (HMG-CoA) reductase inhibitors, also known as statins, are promising agents in this respect. Originally, statins were used in the therapy of dyslipidemia and for the prevention of cardiovascular diseases; however, extensive research has recently been performed to elucidate the functions of statins in bacterial infections and cancers. The mevalonate pathway is essential in the posttranslational modification of proteins related to vital eukaryotic cell functions. In this article, a comparative review is given about the possible role of HMG-CoA reductase inhibitors in managing diseases of bacterial and neoplastic origin. Molecular research and clinical studies have proven the justification of statins in this field. Further well-designed clinical trials are urged to clarify the significance of the contribution of statins to the lower risk of disease progression in bacterial infections and cancerous diseases.

Progress on the pathological tissue microenvironment barrier-modulated nanomedicine

Imbalance in the tissue microenvironment is the main obstacle to drug delivery and distribution in the human body. Before penetrating the pathological tissue microenvironment to the target site, therapeutic agents are usually accompanied by three consumption steps: the first step is tissue physical barriers for prevention of their penetration, the second step is inactivation of them by biological molecules, and the third step is a cytoprotective mechanism for preventing them from functioning on specific subcellular organelles. However, recent studies in drug-hindering mainly focus on normal physiological rather than pathological microenvironment, and the repair of damaged physiological barriers is also rarely discussed. Actually, both the modulation of pathological barriers and the repair of damaged physiological barriers are essential in the disease treatment and the homeostasis maintenance. In this review, we present an overview describing the latest advances in the generality of these pathological barriers and barrier-modulated nanomedicine. Overall, this review holds considerable significance for guiding the design of nanomedicine to increase drug efficacy in the future.

Supramolecular nanomedicines based on host-guest interactions of cyclodextrins

In the biomedical and pharmaceutical fields, cyclodextrin (CD) is undoubtedly one of the most frequently used macrocyclic compounds as the host molecule because it has good biocompatibility and can increase the solubility, bioavailability, and stability of hydrophobic drug guests. In this review, we generalized the unique properties of CDs, CD-related supramolecular nanocarriers, supramolecular controlled release systems, and targeting systems based on CDs, and introduced the paradigms of these nanomedicines. In addition, we also discussed the prospects and challenges of CD-based supramolecular nanomedicines to facilitate the development and clinical translation of these nanomedicines.

New insights into the therapeutic potentials of statins in cancer

The widespread clinical use of statins has contributed to significant reductions of cardiovascular morbidity and mortality. Increasing preclinical and epidemiological evidences have revealed that dyslipidemia is an important risk factor for carcinogenesis, invasion and metastasis, and that statins as powerful inhibitor of HMG-CoA reductase can exert prevention and intervention effects on cancers, and promote sensitivity to anti-cancer drugs. The anti-cancer mechanisms of statins include not only inhibition of cholesterol biosynthesis, but also their pleiotropic effects in modulating angiogenesis, apoptosis, autophagy, tumor metastasis, and tumor microenvironment. Moreover, recent clinical studies have provided growing insights into the therapeutic potentials of statins and the feasibility of combining statins with other anti-cancer agents. Here, we provide an updated review on the application potential of statins in cancer prevention and treatment and summarize the underneath mechanisms, with focuses on data from clinical studies.

Epithelial Ovarian Cancer: A Five Year Review

Ovarian cancer is a malignant disease that affects thousands of patients every year. Currently, we use surgical techniques for early-stage cancer and chemotherapy treatment combinations for advanced stage cancer. Several novel therapies are currently being investigated, with gene therapy and stem cell therapy being the corner stone of this investigation. We conducted a thorough search on PubMed and gathered up-to-date information regarding epithelial ovarian cancer therapies. We present, in the current review, all novel treatments that were investigated in this field over the past five years, with a particular focus on local treatment.

Predicting tumor repopulation through the gene panel derived from radiation resistant colorectal cancer cells

BACKGROUND

Tumor cells with the capability of radiation resistance can escape the fate of cell death after radiotherapy, serving as the main cause of treatment failure. Repopulation of tumors after radiotherapy is dominated by this group of residual cells, which greatly reduce the sensitivity of recurrent tumors to the therapy, resulting in poor clinical outcomes. Therefore, revealing the mechanism of radiation resistant cells participating in tumor repopulation is of vital importance for cancer patients to obtain a better prognosis.

METHODS

Co-expressed genes were searched by using genetic data of radiation resistant cells (from GEO database) and TCGA colorectal cancer. Univariate and multivariate Cox regression analysis were performed to define the most significant co-expressed genes for establishing prognostic indicator. Logistic analysis, WGCNA analysis, and other types of tumors were included to verify the predictive ability of the indicator. RT-qPCR was carried out to test expression level of key genes in colorectal cancer cell lines. Colongenic assay was utilized to test the radio-sensitivity and repopulation ability of key gene knockdown cells.

RESULTS

Prognostic indicator based on TCGA colorectal cancer patients containing four key radiation resistance genes (LGR5, KCNN4, TNS4, CENPH) was established. The indicator was shown to be significantly correlated with the prognosis of colorectal cancer patients undergoing radiotherapy, and also had an acceptable predictive effect in the other five types of cancer. RT-qPCR showed that expression level of key genes was basically consistent with the radiation resistance level of colorectal cancer cells. The clonogenic ability of all key gene knockdown cells decreased after radiation treatment compared with the control groups.

CONCLUSIONS

Our data suggest that LGR5, KCNN4, TNS4 and CENPH are correlated with radiation sensitivity of colorectal cancer cells, and the indicator composed by them can reflect the prognosis of colorectal cancer patients undergoing radiation therapy. Our data provide an evidence of radiation resistant tumor cells involved in tumor repopulation, and give patients undergoing radiotherapy an approving prognostic indicator with regard to tumor progression.

Raloxifene and bazedoxifene as selective ALDH1A1 inhibitors to ameliorate cyclophosphamide resistance: A drug repurposing approach

Cyclophosphamide (CP) is one of the most widely used anticancer drugs for various malignancies. However, its long-term use leads to ALDH1A1-mediated inactivation and subsequent resistance which necessitates the development of potential ALDH1A1 inhibitors. Currently, ALDH1A1 inhibitors from different chemical classes have been reported, but these failed to reach the market due to safety and efficacy problems. Developing a new treatment from the ground requires a huge amount of time, effort, and money, therefore it is worthwhile to improve CP efficacy by proposing better adjuvants as ALDH1A1 inhibitors. Herein, the database constituting the FDA-approved drugs with well-established safety and toxicity profiles was screened through already reported machine learning models by our research group. This model is validated for discriminating the ALDH1A1 inhibitors and non-inhibitors. Virtual screening protocol (VS) from this model identified four FDA-approved drugs, raloxifene, bazedoxifene, avanafil, and betrixaban as selective ALDH1A1 inhibitors. The molecular docking, dynamics, and water swap analysis also suggested these drugs to be promising ALDH1A1 inhibitors which were further validated for their CP resistance reversal potential by in-vitro analysis. The in-vitro enzymatic assay results indicated that raloxifene and bazedoxifene selectively inhibited the ALDH1A1 enzyme with IC₅₀ values of 2.35 and 4.41 μM respectively, whereas IC₅₀ values of both the drugs against ALDH2 and ALDH3A1 was >100 μM. Additional in-vitro stu = dies with well-reported ALDH1A1 overexpressing A549 and MIA paCa-2 cell lines suggested that mafosfamide sensitivity was further ameliorated by the combination of both raloxifene and bazedoxifene. Collectively, in-silico and in-vitro studies indicate raloxifene and bazedoxifene act as promising adjuvants with CP that may improve the quality of treatment for cancer patients with minimal toxicities.

Solid Lipid Nanoparticles: Multitasking Nano-Carriers for Cancer Treatment

Despite all the advances seen in recent years, the severe adverse effects and low specificity of conventional chemotherapy are still challenging problems regarding cancer treatment. Nanotechnology has helped to address these questions, making important contributions in the oncological field. The use of nanoparticles has allowed the improvement of the therapeutic index of several conventional drugs and facilitates the tumoral accumulation and intracellular delivery of complex biomolecules, such as genetic material. Among the wide range of nanotechnology-based drug delivery systems (nanoDDS), solid lipid nanoparticles (SLNs) have emerged as promising systems for delivering different types of cargo. Their solid lipid core, at room and body temperature, provides SLNs with higher stability than other formulations. Moreover, SLNs offer other important features, namely the possibility to perform active targeting, sustained and controlled release, and multifunctional therapy. Furthermore, with the possibility to use biocompatible and physiologic materials and easy scale-up and low-cost production methods, SLNs meet the principal requirements of an ideal nanoDDS. The present work aims to summarize the main aspects related to SLNs, including composition, production methods, and administration routes, as well as to show the most recent studies about the use of SLNs for cancer treatment.

Therapeutic effect of haploidentical peripheral blood stem cell treatment on relapsed/refractory ovarian cancer

The traditional immunotherapy is limited on relapsed/refractory metastatic ovarian cancer because tumors cause immunosuppression. Since new therapeutic strategies to improve clinical outcomes for patients with relapsed/refractory metastatic ovarian carcinoma are needed, the aim of this study was to evaluate the therapeutic effect of haploidentical peripheral blood stem cells (haplo-PBSCs) adoptive treatment on relapsed/refractory ovarian cancer. Thirteen patients with advanced stage of ovarian cancer and refractory history after surgery and chemotherapy were treated with interleukin-2 activated haplo-PBSCs donated by their parents or children. Clinical outcomes including therapeutic response by measuring tumor size changes using CT scanning, CA-125 levels and survival times were evaluated. T and NK cell population in patients before and after treatment was detected by flow cytometry analysis. The median follow-up time after haplo-PBSCs adoptive treatment was 14 months. At the time of the last follow-up, the median overall survival after haplo-PBSCs adoptive treatment was 9.1 months. Ten patients (76.9%) achieved a relief of symptoms, including abdominal distention, ache, fatigue, and poor appetite. During the first 2 months after treatment, CA125 levels decreased in 10 patients (76.9%). Five patients (38.5%) had a stable disease and 1 patient (8%) had partial response. T cell population (CD3⁺CD4⁺ and CD3⁺CD8⁺) and CD3^-CD16⁺CD56⁺ NK cells were increased in patients after haplo-PBSCs adoptive treatment. Our study reveals that haplo-PBSCs adoptive treatment is associated with an anti-tumor effect and increasing immune responses in patients with relapsed/refractory ovarian cancer.

Cutting Off H+ Leaks on the Inner Mitochondrial Membrane: A Proton Modulation Approach to Selectively Eradicate Cancer Stem Cells

Cancer stem cells (CSCs) are associated with the invasion and metastatic relapse of various cancers. However, current cancer therapies are limited to targeting the bulk of primary tumor cells while remaining the CSCs untouched. Here, we report a new proton (H⁺) modulation approach to selectively eradicate CSCs via cutting off the H⁺ leaks on the inner mitochondrial membrane (IMM). Based on the fruit extract of Gardenia jasminoides, a multimodal molecule channel blocker with high biosafety, namely, Bo-Mt-Ge, is developed. Importantly, in this study, we successfully identify that mitochondrial uncoupling protein UCP2 is closely correlated with the stemness of CSCs, which may offer a new perspective for selective CSC drug discovery. Mechanistic studies show that Bo-Mt-Ge can specifically inhibit the UCP2 activities, decrease the H⁺ influx in the matrix, regulate the electrochemical gradient, and deplete the endogenous GSH, which synergistically constitute a unique MoA to active apoptotic CSC death. Intriguingly, Bo-Mt-Ge also counteracts the therapeutic resistance via a two-pronged tactic: drug efflux pump P-glycoprotein downregulation and antiapoptotic factor (e.g., Bcl-2) inhibition. With these merits, Bo-Mt-Ge proved to be one of the safest and most efficacious anti-CSC agents, with ca. 100-fold more potent than genipin alone in vitro and in vivo. This study offers new insights and promising solutions for future CSC therapies in the clinic.

Supramolecular hydrogel for programmable delivery of therapeutics to cancer multidrug resistance

Multidrug resistance (MDR) has been considered as a major adversary in oncologic chemotherapy. To simultaneously overcome drug resistance and inhibit tumor growth, it is essential to develop a drug delivery system that can carry and release multiple therapeutic agents with spatiotemporal control. In this study, we developed a hydrogel containing an enzyme-cleavable peptide motif, with a network structure formed by 4-armed polyethylene glycol (PEG) crosslinked by complementary nucleic acid sequences. Hydrogen bond formation between nucleobase pairing allows the hydrogel to be injectable, and the peptide motif grants deliberate control over hydrogel degradation and the responsive drug release. Moreover, MDR-targeted siRNAs are complexed with stearyl-octaarginine (STR-R8), while doxorubicin (Dox) is intercalated with DNA and nanoclay structures in this hydrogel to enhance therapeutic efficacy and overcome MDR. The results show a successful configuration of a hydrogel network with in situ gelation property, injectability, and degradability in the presence of tumor-associated enzyme, MMP-2. The synergistic effect by combining MDR-targeted siRNAs and Dox manifests with the enhanced anti-cancer effect on drug resistant breast cancer cells in both in vitro and in vivo tumor models. We suggest that with the tailor-designed hydrogel system, multidrug resistance in tumor cells can be significantly inhibited by the co-delivery of multiple therapeutics with spatial-temporal control release.

Dual Sensitization Anti-Resistant Nanoparticles for Treating Refractory Breast Cancers via Apoptosis-Inducing

Purpose

Current chemotherapy fails to offer a desirable efficacy in clinical treatment against breast cancer due to the extensive multi-drug resistance. In this study, we developed dual sensitization anti-resistant nanoparticles to treat refractory breast cancer, aiming to benefit from photodynamic therapy and chemotherapy.

Methods

Hyaluronic acid (HA) derivative and photosensitizer chlorin e6 (Ce6) derivative were synthesized and confirmed by mass spectrometry. These derivatives and the chemotherapy agent paclitaxel were incorporated into nanoparticles by an emulsion-solvent evaporation method. The prepared nanoparticles were characterized by dynamic laser scattering, atomic force microscopy, and high performance liquid chromatography (HPLC). The efficacy and mechanisms of the nanoparticles, both in vitro and in vivo, were investigated by flow cytometry, confocal/fluorescence microscopy, and a high-content screening system.

Results

The prepared dual sensitization anti-resistant nanoparticles were round with a diameter of ~ 100 nm, exhibiting high encapsulation efficiency for the anticancer agent paclitaxel. The nanoparticles demonstrated a robust inhibitory effect against drug-resistant breast cancer cells by enhanced uptake, synergistic effect of photodynamic therapy and chemotherapy, and apoptosis-inducing via multiple pathways. In vivo efficacy, biocompatibility and safety were further confirmed acceptable in tumor-bearing mice.

Conclusion

The prepared dual sensitization anti-resistant nanoparticles were promising to treat refractory breast cancer with a controllable treatment site and minimal side effects.

Nrf2-siRNA Enhanced the Anti-Tumor Effects of As2O3 in 5-Fluorouracil-Resistant Hepatocellular Carcinoma by Inhibiting HIF-1α/HSP70 Signaling

Purpose

Chemoresistance is a major factor contributing to the failure of cancer treatment. The conventional chemotherapy agent 5-fluorouracil (5-FU) has been used for cancer treatment for decades. However, its use is limited in the treatment of hepatocellular carcinoma (HCC) due to acquired resistance. Nrf2 (NF-E2-related factor 2) is known to be associated with drug resistance across a wide range of cancer types. Also, since arsenic trioxide (As₂O₃) showed antitumor effects on HCC, the purpose of this study was to determine whether As₂O₃ and Nrf2-siRNA could inhibit HCC synergistically.

Methods

We generated two separate 5-FU-resistant HCC cell lines (SNU-387/5-FU and Hep3B/5-FU). Western blotting was used to determine protein levels. An efficient lentiviral delivery system was used to establish stable knockdown or overexpression of Nrf2 and HIF-1α. In vitro and in vivo analyses of the effects of Nrf2 gene knockdown and As₂O₃ on 5-FU-resistant HCC cells were conducted.

Results

The expression of Nrf2 was higher in the 5-FU-resistant HCC cell lines than in the parental cell lines. When coupled with Nrf2 knockdown, As₂O₃ treatment significantly decreased 5-FU-resistant SNU-387 and Hep3B cell viability, migration, and invasion, inactivated HIF-1α/HSP70 signaling, inhibited anti-apoptotic B-cell lymphoma (Bcl-2) activity, and increased the expression of pro-apoptotic Bcl-2-associated X protein (BAX) along with caspase-3. The synergistic effect was also confirmed using a 5-FU-resistant Hep3B mouse xenograft model in vivo.

Conclusion

Nrf2 knockdown could improve the effect of As₂O₃ on reversing drug resistance in 5-FU-resistant HCC cells.

Convergent synthesis of tetrahydropyranyl side chain of verucopeptin, an antitumor antibiotic active against multidrug-resistant cancers

A concise synthesis of the tetrahydropyranyl side chain of verucopeptin, an antitumor antibiotic cyclodepsipeptide efficacious against MDR cancers in vivo, is achieved using 12 steps in the longest linear sequence and 21 total steps, in which Julia-Kocienski olefination for the segments coupling, asymmetric hydroxylation as well as stereoselective synthesis of stable tetrahydropyran ring from a D-isoascorbic acid derivative are key steps. This convergent synthetic strategy enables the structural modification and mechanism study of verucopeptin for its clinical applications.

Molecular mechanism of circRNAs in drug resistance in renal cell carcinoma

Renal cell carcinoma (RCC) is one of the most common malignant tumors with a poor response to radiotherapy and chemotherapy. The advent of molecular targeted drugs has initiated great breakthroughs in the treatment of RCC. However, drug resistance to targeted drugs has become an urgent problem. Various studies across the decades have confirmed the involvement of circular RNAs (circRNAs) in multiple pathophysiological processes and its abnormal expression in many malignant tumors. This review speculated that circRNAs can provide a new solution to drug resistance in RCC and perhaps be used as essential markers for the early diagnosis and prognosis of RCC. Through the analysis and discussion of relevant recent research, this review explored the relationship of circRNAs to and their regulatory mechanisms in drug resistance in RCC. The results indicate an association between the expression of circRNAs and the development of RCC, as well as the involvement of circRNAs in drug resistance in RCC.

Discovery of the Potentiator of the Pore-Forming Ability of Lantibiotic Nisin: Perspectives for Anticancer Therapy

This study was focused on the action of lantibiotic nisin on the phospholipid membranes. Nisin did not produce ion-permeable pores in the membranes composed of DOPC or DOPE. The introduction of DOPS into bilayer lipid composition led to a decrease in the threshold detergent concentration of nisin. An addition of nisin to DOPG- and TOCL-enriched bilayers caused the formation of well-defined ion pores of various conductances. The transmembrane macroscopic current increased with the second power of the lantibiotic aqueous concentration, suggesting that the dimer of nisin was at least involved in the formation of conductive subunit. The pore-forming ability of lantibiotic decreased in the series: DOPC/TOCL ≈ DOPE/TOCL >> DOPC/DOPG ≥ DOPE/DOPG. The preferential interaction of nisin to cardiolipin-enriched bilayers might explain its antitumor activity by pore-formation in mitochondrial membranes. Small natural molecules, phloretin and capsaicin, were found to potentiate the membrane activity of nisin in the TOCL-containing membranes. The effect was referred to as changes in the membrane boundary potential at the adsorption of small molecules. We concluded that the compounds diminishing the membrane boundary potential should be considered as the potentiator of the nisin pore-forming ability that can be used to develop innovative formulations for anticancer therapy.

The role of lncRNA H19 in tumorigenesis and drug resistance of human Cancers

Systemic therapy is one of the most significant cancer treatments. However, drug resistance often appears and has become the primary cause of cancer therapy failure. Regulation of drug target, drug metabolism and drug efflux, cell death escape (apoptosis, autophagy, et al.), epigenetic changes, and many other variables are complicatedly involved in the mechanisms of drug resistance. In various types of cancers, long non-coding RNA H19 (lncRNA H19) has been shown to play critical roles in tumor development, proliferation, metastasis, and multiple drug resistance as well. The efficacy of chemotherapy, endocrine therapy, and targeted therapy are all influenced by the expression of H19, especially in breast cancer, liver cancer, lung cancer and colorectal cancer. Here, we summarize the relationship between lncRNA H19 and tumorigenesis, and illustrate the drug resistance mechanisms caused by lncRNA H19 as well. This review may provide more therapeutic potential targets for future cancer treatments.

Cisplatin Resistance: Genetic and Epigenetic Factors Involved

Cisplatin (CDDP) is the drug of choice against different types of cancer. However, tumor cells can acquire resistance to the damage caused by cisplatin, generating genetic and epigenetic changes that lead to the generation of resistance and the activation of intrinsic resistance mechanisms in cancer cells. Among them, we can find mutations, alternative splicing, epigenetic-driven expression changes, and even post-translational modifications of proteins. However, the molecular mechanisms by which CDDP resistance develops are not clear but are believed to be multi-factorial. This article highlights a description of cisplatin, which includes action mechanism, resistance, and epigenetic factors involved in cisplatin resistance.

Curcumin Modulates Oxidative Stress, Fibrosis, and Apoptosis in Drug-Resistant Cancer Cell Lines

In cancer management, drug resistance remains a challenge that reduces the effectiveness of chemotherapy. Several studies have shown that curcumin resensitizes cancer cells to chemotherapeutic drugs to overcome resistance. In the present study, we investigate the potential therapeutic role of curcumin in regulating the proliferation of drug-resistant cancers. Six drug-sensitive (MCF7, HCT116, and A549) and -resistant (MCF7/TH, HCT116R, and A549/ADR) cancer cell lines were treated with curcumin followed by an analysis of cytotoxicity, LDH enzyme, total reactive oxygen species, antioxidant enzymes (SOD and CAT), fibrosis markers (TGF-β1 protein, fibronectin, and hydroxyproline), and expression of cellular apoptotic markers (Bcl-2, Bax, Bax/Bcl-2 ratio, Annexin V, cytochrome c, and caspase-8). Additionally, the expression of cellular SIRT1 was estimated by ELISA and RT-PCR analysis. Curcumin treatment at doses of 2.7–54.3 µM significantly reduced the growth of sensitive and resistant cells as supported with decreased viability and increased cellular LDH enzyme of treated cells compared to controls non-treated cells. Curcumin also at doses of 2.7 and 54.3 µM regulated the fibrogenesis by reducing the expression of fibrotic markers in treated cells. Analysis of apoptotic markers indicated increased Bax, Bax, Bax/Bcl-2 ratio, Annexin V, caspase-8, and cytochrome c expression, while Bcl-2 expressions were significantly reduced. In curcumin-treated cells at 2.7 μM, non-significant change in ROS with significant increase in SOD and CAT activity was observed, whereas an increase in ROS with a reduction in respective antioxidant enzymes were seen at higher concentrations along with significant upregulation of SIRT1. In conclusion, the present study shows that curcumin induces anticancer activity against resistant cancer cell lines in a concentration- and time-dependent manner. The protective activities of curcumin against the growth of cancer cells are mediated by modulating oxidative stress, regulating fibrosis, SIRT1 activation, and inducing cellular apoptosis. Therefore, curcumin could be tested as an auxiliary therapeutic agent to improve the prognosis in patients with resistant cancers.

Sequentially Activatable Polypeptide Nanoparticles for Combinatory Photodynamic Chemotherapy of Breast Cancer

Stimuli-activatable nanomaterials hold significant promise for tumor-specific drug delivery by recognizing the internal or external stimulus. Herein, we reported a dual-responsive and biodegradable polypeptide nanoparticle (PPTP@PTX₂ NP) for combinatory chemotherapy and photodynamic therapy (PDT) of breast cancer. The NPs were engineered by encapsulating diselenide bond linked dimeric prodrug of paclitaxel (PTX₂) in an intracellular acidity-activatable polypeptide micelle. Specifically, the acid-responsive polypeptide was synthesized by grafting a tetraphenyl porphyrin (TPP) photosensitizer and N,N-diisopropylethylenediamine (DPA) onto the poly(ethylene glycol)-block-poly(glutamic acid) diblock copolymer by the amidation reaction, which self-assembled into micellar NPs and was activated inside the acidic endocytic vesicles to perform PDT. The paclitaxel dimer can be stably loaded into the polypeptide NPs and be restored by PDT inside the tumor cells. The formed PPTP@PTX₂ NPs remained inert during blood circulation and passively accumulated in the tumor foci, which could be activated within the endocytic vesicles via acid-triggered protonation of DPA groups to generate fluorescence signal and release PTX₂ in 4T1 murine breast tumor cells. Upon 660 nm laser irradiation, the activated NPs carried out PDT via TPP and chemotherapy via PTX to induce apoptosis of 4T1 cells and thereby efficiently inhibited 4T1 tumor growth and prevented metastasis of tumor cells.

Activation of the Anaphase Promoting Complex Reverses Multiple Drug Resistant Cancer in a Canine Model of Multiple Drug Resistant Lymphoma

Simple Summary

Multiple drug resistant cancers develop all too soon in patients who received successful cancer treatment. A lack of treatment options often leaves palliative care as the last resort. We tested whether the insulin sensitizer, metformin, known to have anti-cancer activity, could impact canines with drug resistant lymphoma when added to chemotherapy. All canines in the study expressed protein markers of drug resistance and within weeks of receiving metformin, the markers were decreased. A microarray was performed, and from four canines assessed, a common set of 290 elevated genes were discovered in tumor cells compared to control cells. This cluster was enriched with genes that stall the cell cycle, with a large component representing substrates of the Anaphase Promoting Complex (APC), which degrades proteins. One canine entered partial remission. RNAs from this canine showed that APC substrates were decreased during remission and elevated again during relapse, suggesting that the APC was impaired in drug resistant canines and restored when remission occurred. We validated our results in cell lines using APC inhibitors and activators. We conclude that the APC may be a vital guardian of the genome and could delay the onset of multiple drug resistance when activated.

Abstract

Like humans, canine lymphomas are treated by chemotherapy cocktails and frequently develop multiple drug resistance (MDR). Their shortened clinical timelines and tumor accessibility make canines excellent models to study MDR mechanisms. Insulin-sensitizers have been shown to reduce the incidence of cancer in humans prescribed them, and we previously demonstrated that they also reverse and delay MDR development in vitro. Here, we treated canines with MDR lymphoma with metformin to assess clinical and tumoral responses, including changes in MDR biomarkers, and used mRNA microarrays to determine differential gene expression. Metformin reduced MDR protein markers in all canines in the study. Microarrays performed on mRNAs gathered through longitudinal tumor sampling identified a 290 gene set that was enriched in Anaphase Promoting Complex (APC) substrates and additional mRNAs associated with slowed mitotic progression in MDR samples compared to skin controls. mRNAs from a canine that went into remission showed that APC substrate mRNAs were decreased, indicating that the APC was activated during remission. In vitro validation using canine lymphoma cells selected for resistance to chemotherapeutic drugs confirmed that APC activation restored MDR chemosensitivity, and that APC activity was reduced in MDR cells. This supports the idea that rapidly pushing MDR cells that harbor high loads of chromosome instability through mitosis, by activating the APC, contributes to improved survival and disease-free duration.