ABCC3 is a novel target for the treatment of pancreatic cancer. Adv Biol Regul. 2019;. [PMID: 31053501 DOI: 10.1016/j.jbior.2019.04.004]

MiRNAs: main players of cancer drug resistance target ABC transporters

Chemotherapy remains the cornerstone of cancer treatment; however, its efficacy is frequently compromised by the development of chemoresistance. Multidrug resistance (MDR), characterized by the refractoriness of cancer cells to a wide array of chemotherapeutic agents, presents a significant barrier to achieving successful and sustained cancer remission. One critical factor contributing to this chemoresistance is the overexpression of ATP-binding cassette (ABC) transporters. Furthermore, additional mechanisms, such as the malfunctioning of apoptosis, alterations in DNA repair systems, and resistance mechanisms inherent to cancer stem cells, exacerbate the issue. Intriguingly, microRNAs (miRNAs) have demonstrated potential in modulating chemoresistance by specifically targeting ABC transporters, thereby offering promising new avenues for overcoming drug resistance. This narrative review aims to elucidate the molecular underpinnings of drug resistance, with a particular focus on the roles of ABC transporters and the regulatory influence of miRNAs on these transporters.

Targeting Drug Resistance in Cancer: Dimethoxycurcumin as a Functional Antioxidant Targeting ABCC3

The development of new anticancer therapies remains challenging due to tumor heterogeneity and the frequent emergence of multidrug resistance (MDR). Natural products have garnered increasing attention as alternative or complementary therapeutic agents due to their bioactivity and reduced toxicity. Polyphenols, particularly curcumin and its derivatives, have shown promise in modulating signaling pathways, enhancing chemosensitivity, and overcoming drug resistance. The anticancer potential of dimethoxycurcumin, a chemically modified curcumin derivative identified through consensus fingerprint similarity screening, was investigated for its potential to inhibit ABCC3 (MRP3)-a member of the ATP-binding cassette (ABC) transporter family implicated in drug efflux, tumor cell survival, and resistance. In vitro experiments demonstrated that dimethoxycurcumin significantly reduced cancer cell viability and colony formation, indicating a strong inhibitory effect on ABCC3 function. These results suggest that dimethoxycurcumin may sensitize cancer cells to chemotherapy by targeting resistance pathways. The data presented contribute to the growing body of evidence suggesting that bioactive plant-derived compounds, including chemically modified derivatives, may hold therapeutic potential in oncology by modulating multidrug resistance pathways. Targeting ABC transporters with natural compound derivatives could offer a promising strategy for developing more effective and less toxic anticancer therapies.

ABCC3 Is a Differential Marker of CYP11B2-Negative Zona Glomerulosa Cells in Human Adrenal Cortex

ATP Binding Cassette Subfamily C Member 3 (ABCC3) is a membrane transporter that exports diverse compounds, influencing drug resistance in cancers and impacting metabolic and malignant diseases. We previously reported ABCC3 upregulation in human adrenal cells under lipid peroxidation-induced oxidative stress. We investigated ABCC3 expression and function in the human adrenal cortex in the context of primary aldosteronism, focusing on its relationship to CYP11B2 (aldosterone synthase) in zona glomerulosa (ZG) cells and aldosterone-producing lesions. ABCC3 expression in aldosterone-producing adenomas (APAs) was markedly reduced compared to the adjacent adrenal cortex, cortisol-producing adenomas, and non-functioning adenomas. The reduction in APAs showed genotypic variability: in APAs harboring KCNJ5 mutations-known drivers of autonomous aldosterone production via altered potassium channel function-ABCC3 mRNA/protein levels were significantly higher than in wild-type KCNJ5 APAs. Spatial transcriptomics and immunofluorescence colocalization revealed an inverse expression pattern between ABCC3 and CYP11B2 (aldosterone synthase) in APAs and aldosterone-producing micronodules (APMs). Notably, high ABCC3 expression was exclusively observed in adrenal ZG cells that lacked CYP11B2 expression. This expression pattern distinguishes ABCC3 from common ZG markers such as KCNJ5 and DAB2, which are expressed across adrenal ZG cells, APMs, and APA tumor cells. In cultured human adrenocortical cells, both angiotensin II stimulation and induced expression of the KCNJ5-L168R mutation resulted in upregulation of CYP11B2 transcription while concomitantly suppressing ABCC3 expression. In conclusion, ABCC3 serves as a novel marker of CYP11B2-negative ZG cells, providing a histopathological tool to differentiate normal adrenal zonation from aldosterone-producing lesions in primary aldosteronism, as well as from cortisol-producing and nonfunctional adenomas.

Exploring bile acid transporters as key players in cancer development and treatment: Evidence from preclinical and clinical studies

Bile acid transporters (BATs) are integral membrane proteins belonging to various families, such as solute carriers, organic anion transporters, and ATP-binding cassette families. These transporters play a crucial role in bile acid transportation within the portal and systemic circulations, with expression observed in tissues, including the liver, kidney, and small intestine. Bile acids serve as signaling molecules facilitating the absorption and reabsorption of fats and lipids. Dysregulation of bile acid concentration has been implicated in tumorigenesis, yet the role of BATs in this process remains underexplored. Emerging evidence suggests that BATs may modulate various stages of cancer progression, including initiation, development, proliferation, metastasis, and tumor microenvironment regulation. Targeting BATs using siRNAs, miRNAs, and small compound inhibitors in preclinical models and their polymorphisms are well-studied for transporters like BSEP, MDR1, MRP2, OATP1A2, etc., and have shed light on their involvement in tumorigenesis, particularly in cancers such as those affecting the liver and gastrointestinal tract. While BATs' role in diseases like Alagille syndrome, biliary atresia, and cirrhosis have been extensively studied, their implications in cancer warrant further investigation. This review highlights the expression and function of BATs in cancer development and emphasizes the potential of targeting these transporters as a novel therapeutic strategy for various malignancies.

Sensitizing cholangiocarcinoma to chemotherapy by inhibition of the drug-export pump MRP3

AIMS

Drug export through ABC proteins hinders cancer response to chemotherapy. Here, we have evaluated the relevance of MRP3 (ABCC3) in cholangiocarcinoma (CCA) as a potential target to overcome drug resistance.

METHODS

Gene expression was analyzed in silico using the TCGA-CHOL database and experimentally (mRNA and protein) in resected CCA tumors. The effect of manipulating MRP3 function/expression was evaluated in vitro and in vivo.

RESULTS

High MRP3 expression at the plasma membrane of human CCA cells was found. MRP3 overexpression in HEK293T cells selectively impaired the cytotoxic effect of etoposide, cisplatin, SN-38, and mitoxantrone. Reduced MRP3 activity with shRNAs or pan-MRP blockers enhanced the sensitivity to these drugs. MRP3 interaction with natural and semisynthetic compounds (≈40,000) was evaluated by virtual drug screening and molecular docking. Two identified potential MRP3 inhibitors (EM-114, EM-188), and sorafenib impaired MRP3 transport activity and enhanced sensitivity of CCA cells to etoposide and cisplatin. The antitumor effect of cisplatin in the mouse xenograft model was enhanced by co-treatment with sorafenib, which was accompanied by a higher intratumor accumulation of cisplatin.

CONCLUSIONS

Genetic and pharmacological MRP3 inhibition enhances the anti-CCA effect of several drugs, which constitutes a promising strategy to improve the response to chemotherapy in CCA patients.

MicroRNA-34 and gastrointestinal cancers: a player with big functions

It is commonly assumed that gastrointestinal cancer is the most common form of cancer across the globe and is the leading contributor to cancer-related death. The intricate mechanisms underlying the growth of GI cancers have been identified. It is worth mentioning that both non-coding RNAs (ncRNAs) and certain types of RNA, such as circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and microRNAs (miRNAs), can have considerable impact on the development of gastrointestinal (GI) cancers. As a tumour suppressor, in the group of short non-coding regulatory RNAs is miR-34a. miR-34a silences multiple proto-oncogenes at the post-transcriptional stage by targeting them, which inhibits all physiologically relevant cell proliferation pathways. However, it has been discovered that deregulation of miR-34a plays important roles in the growth of tumors and the development of cancer, including invasion, metastasis, and the tumor-associated epithelial-mesenchymal transition (EMT). Further understanding of miR-34a's molecular pathways in cancer is also necessary for the development of precise diagnoses and effective treatments. We outlined the most recent research on miR-34a functions in GI cancers in this review. Additionally, we emphasize the significance of exosomal miR-34 in gastrointestinal cancers.

Genetic and phenotypic profiling of single living circulating tumor cells from patients with microfluidics

Accurate prediction of the efficacy of immunotherapy for cancer patients through the characterization of both genetic and phenotypic heterogeneity in individual patient cells holds great promise in informing targeted treatments, and ultimately in improving care pathways and clinical outcomes. Here, we describe the nanoplatform for interrogating living cell host-gene and (micro-)environment (NICHE) relationships, that integrates micro- and nanofluidics to enable highly efficient capture of circulating tumor cells (CTCs) from blood samples. The platform uses a unique nanopore-enhanced electrodelivery system that efficiently and rapidly integrates stable multichannel fluorescence probes into living CTCs for in situ quantification of target gene expression, while on-chip coculturing of CTCs with immune cells allows for the real-time correlative quantification of their phenotypic heterogeneities in response to immune checkpoint inhibitors (ICI). The NICHE microfluidic device provides a unique ability to perform both gene expression and phenotypic analysis on the same single cells in situ, allowing us to generate a predictive index for screening patients who could benefit from ICI. This index, which simultaneously integrates the heterogeneity of single cellular responses for both gene expression and phenotype, was validated by clinically tracing 80 non-small cell lung cancer patients, demonstrating significantly higher AUC (area under the curve) (0.906) than current clinical reference for immunotherapy prediction.

Identification of ABCC3 and its isoforms as potential biomarker in hepatocellular carcinoma

Liver diseases preceding the occurrence of hepatocellular carcinoma (HCC) play a crucial role in the progression and establishment of HCC, a malignancy ranked as the third deadliest cancer worldwide. Late diagnosis, alongside ineffective treatment, leads patients to a poor survival rate. This scenario argues for seeking novel alternatives for detecting liver alterations preceding the early occurrence of HCC. Experimental studies have reported that ABCC3 protein increases within HCC tumors but not in adjacent tissue. Therefore, we analyzed ABCC3 expression in public databases and investigated the presence of ABCC3 and its isoforms in plasma, urine and its release in extracellular vesicles (EVs) cargo from patients bearing cirrhosis and HCC. The UALCAN and GEPIA databases were used to analyze the expression of ABCC3 in HCC. The results were validated in a case-control study including 41 individuals bearing cirrhosis and HCC, and the levels of ABCC3 in plasma and urine samples, as well as EVs, were analyzed by ELISA and western blot. Our data showed that ABCC3 expression was higher in HCC tissues than in normal tissues and correlated with HCC grade and stage. ABCC3 protein levels were highly increased in both plasma and urine and correlated with liver disease progression and severity. The isoforms MRP3A and MRP3B of ABCC3 were significantly increased in both EVs and plasma/urine of patients bearing HCC. ABCC3 expression gradually increases in HCC tissues, and its protein levels are increased in both plasma and urine of patients with cirrhosis and HCC. MRP3A and MRP3B isoforms have the potential to be prognostic biomarkers of HCC.

Synergistic Anticancer Activity of Plumbagin and Xanthohumol Combination on Pancreatic Cancer Models

Among diverse cancers, pancreatic cancer is one of the most aggressive types due to inadequate diagnostic options and treatments available. Therefore, there is a necessity to use combination chemotherapy options to overcome the chemoresistance of pancreatic cancer cells. Plumbagin and xanthohumol, natural compounds isolated from the Plumbaginaceae family and Humulus lupulus, respectively, have been used to treat various cancers. In this study, we investigated the anticancer effects of a combination of plumbagin and xanthohumol on pancreatic cancer models, as well as the underlying mechanism. We have screened in vitro numerous plant-derived extracts and compounds and tested in vivo the most effective combination, plumbagin and xanthohumol, using a transgenic model of pancreatic cancer KPC (KrasLSL.G12D/+; p53R172H/+; PdxCretg/+). A significant synergistic anticancer activity of plumbagin and xanthohumol combinations on different pancreatic cancer cell lines was found. The combination treatment of plumbagin and xanthohumol influences the levels of B-cell lymphoma (BCL2), which are known to be associated with apoptosis in both cell lysates and tissues. More importantly, the survival of a transgenic mouse model of pancreatic cancer KPC treated with a combination of plumbagin and xanthohumol was significantly increased, and the effect on BCL2 levels has been confirmed. These results provide a foundation for a potential new treatment for pancreatic cancer based on plumbagin and xanthohumol combinations.

Nanobodies targeting ABCC3 for immunotargeted applications in glioblastoma

The cancer "omics" reveal many clinically relevant alterations that are transforming the molecular characterization of glioblastomas. However, many of these findings are not yet translated into clinical practice due, in part, to the lack of non-invasive biomarkers and the limitations imposed by the blood-brain barrier. Nanobodies, camelid single-domain antibody fragments, emerge as a promising tool for immunotargeted applications for diagnosing and treating glioblastomas. Performing agnostic bioinformatic analysis from glioblastoma patient datasets, we identified ATP Binding Cassette subfamily C member 3 (ABCC3) as a suitable target for immunotargeted applications. The expression of ABCC3 is associated with poor survival and impaired response to temozolomide. Importantly, high expression of ABCC3 is restricted to glioblastoma, with negligible levels in healthy brain tissue, and further correlates with tumor grade and stemness markers. We identified three immunogenic epitopes of ABCC3 which were used to isolate nanobodies from a glioblastoma-specific phage-display nanobody library. Two nanobodies targeting ABCC3 (NbA42 and NbA213) were further characterized and demonstrated in vivo selective recognition of ABCC3 in glioblastoma xenograft mouse models upon systemic administration. We designate NbA42 and NbA213 as new candidates to implement immunotargeted applications guiding a more personalized and precise diagnosis, monitoring, and treatment of glioblastoma patients.

Interplay Between the Histone Variant H2A.Z and the Epigenome in Pancreatic Cancer

BACKGROUND

The oncogenic process is orchestrated by a complex network of chromatin remodeling elements that shape the cancer epigenome. Histone variant H2A.Z regulates DNA control elements such as promoters and enhancers in different types of cancer; however, the interplay between H2A.Z and the pancreatic cancer epigenome is unknown.

OBJECTIVE

This study analyzed the role of H2A.Z in different DNA regulatory elements.

METHODS

We performed Chromatin Immunoprecipitation Sequencing assays (ChiP-seq) with total H2A.Z and acetylated H2A.Z (acH2A.Z) antibodies and analyzed published data from ChIP-seq, RNA-seq, bromouridine labeling-UV and sequencing (BruUV-seq), Hi-C and ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) in the pancreatic cancer cell line PANC-1.

RESULTS

The results indicate that total H2A.Z facilitates the recruitment of RNA polymerase II and transcription factors at promoters and enhancers allowing the expression of pro-oncogenic genes. Interestingly, we demonstrated that H2A.Z is enriched in super-enhancers (SEs) contributing to the transcriptional activation of key genes implicated in tumor development. Importantly, we established that H2A.Z contributes to the three-dimensional (3D) genome organization of pancreatic cancer and that it is a component of the Topological Associated Domains (TADs) boundaries in PANC-1 and that total H2A.Z and acH2A.Z are associated with A and B compartments, respectively.

CONCLUSIONS

H2A.Z participates in the biology and development of pancreatic cancer by generating a pro-oncogenic transcriptome through its posttranslational modifications, interactions with different partners, and regulatory elements, contributing to the oncogenic 3D genome organization. These data allow us to understand the molecular mechanisms that promote an oncogenic transcriptome in pancreatic cancer mediated by H2A.Z.

Expression of Chemoresistance-Associated ABC Proteins in Hepatobiliary, Pancreatic and Gastrointestinal Cancers

Simple Summary

One-third of the approximately 10 million deaths yearly caused by cancer worldwide are due to hepatobiliary, pancreatic, and gastrointestinal tumors. One primary reason for this high mortality is the lack of response of these cancers to pharmacological treatment. More than 100 genes have been identified as responsible for seven mechanisms of chemoresistance, but only a few of them play a critical role. These include ABC proteins (mainly MDR1, MRP1-6, and BCRP), whose expression pattern greatly determines the individual sensitivity of each tumor to pharmacotherapy.

Abstract

Hepatobiliary, pancreatic, and gastrointestinal cancers account for 36% of the ten million deaths caused by cancer worldwide every year. The two main reasons for this high mortality are their late diagnosis and their high refractoriness to pharmacological treatments, regardless of whether these are based on classical chemotherapeutic agents, targeted drugs, or newer immunomodulators. Mechanisms of chemoresistance (MOC) defining the multidrug resistance (MDR) phenotype of each tumor depend on the synergic function of proteins encoded by more than one hundred genes classified into seven groups (MOC1-7). Among them, the efflux of active agents from cancer cells across the plasma membrane caused by members of the superfamily of ATP-binding cassette (ABC) proteins (MOC-1b) plays a crucial role in determining tumor MDR. Although seven families of human ABC proteins are known, only a few pumps (mainly MDR1, MRP1-6, and BCRP) have been associated with reducing drug content and hence inducing chemoresistance in hepatobiliary, pancreatic, and gastrointestinal cancer cells. The present descriptive review, which compiles the updated information on the expression of these ABC proteins, will be helpful because there is still some confusion on the actual relevance of these pumps in response to pharmacological regimens currently used in treating these cancers. Moreover, we aim to define the MOC pattern on a tumor-by-tumor basis, even in a dynamic way, because it can vary during tumor progression and in response to chemotherapy. This information is indispensable for developing novel strategies for sensitization.

Clinicopathological and Prognostic Significance of ABCC3 in Human Glioma

Glioma is the most common malignant primary brain tumor with an inferior survival period and unsatisfactory prognoses. Identification of novel biomarkers is important for the improvements of clinical outcomes of glioma patients. In recent years, more and more biomarkers were identified in many types of tumors. However, the sensitive markers for diagnoses and prognoses of patients with glioma remained unknown. In the present research, our team intended to explore the expression and clinical significance of ABCC3 in glioma patients. Sequential data filtration (survival analyses, independent prognosis analyses, ROC curve analyses, and clinical association analyses) was completed, which gave rise to the determination of the relationship between glioma and the ABCC3 gene. Clinical assays on the foundation of CGGA and TCGA datasets unveiled that ABCC3 expression was distinctly upregulated in glioma and predicted a shorter overall survival. In the multivariable Cox analysis, our team discovered that the expression of ABCC3 was an independent prognosis marker for both 5-year OS (HR = 1.118, 95% CI: 1.052-1.188; P < 0.001). Moreover, our team also studied the association between ABCC3 expression and clinical features of glioma patients, finding that differential expression of ABCC3 was remarkably related to age, 1p19q codeletion, PRS type, chemo status, grade, IDH mutation state, and histology. Overall, our findings suggested ABCC3 might be a novel prognosis marker in glioma.

The Role of TRIP6, ABCC3 and CPS1 Expression in Resistance of Ovarian Cancer to Taxanes

The main problem precluding successful therapy with conventional taxanes is de novo or acquired resistance to taxanes. Therefore, novel experimental taxane derivatives (Stony Brook taxanes; SB-Ts) are synthesized and tested as potential drugs against resistant solid tumors. Recently, we reported alterations in ABCC3, CPS1, and TRIP6 gene expression in a breast cancer cell line resistant to paclitaxel. The present study aimed to investigate gene expression changes of these three candidate molecules in the highly resistant ovarian carcinoma cells in vitro and corresponding in vivo models treated with paclitaxel and new experimental Stony Brook taxanes of the third generation (SB-T-121605 and SB-T-121606). We also addressed their prognostic meaning in ovarian carcinoma patients treated with taxanes. We estimated and observed changes in mRNA and protein profiles of ABCC3, CPS1, and TRIP6 in resistant and sensitive ovarian cancer cells and after the treatment of resistant ovarian cancer models with paclitaxel and Stony Brook taxanes in vitro and in vivo. Combining Stony Brook taxanes with paclitaxel caused downregulation of CPS1 in the paclitaxel-resistant mouse xenograft tumor model in vivo. Moreover, CPS1 overexpression seems to play a role of a prognostic biomarker of epithelial ovarian carcinoma patients’ poor survival. ABCC3 was overexpressed in EOC tumors, but after the treatment with taxanes, its up-regulation disappeared. Based on our results, we can suggest ABCC3 and CPS1 for further investigations as potential therapeutic targets in human cancers.

Role of multidrug resistance-associated proteins in cancer therapeutics: past, present, and future perspectives

Cancer, a major public health problem, is one of the world's top leading causes of death. Common treatments for cancer include cytotoxic chemotherapy, surgery, targeted drugs, endocrine therapy, and immunotherapy. However, despite the outstanding achievements in cancer therapies during the last years, resistance to conventional chemotherapeutic agents and new targeted drugs is still the major challenge. In the present review, we explain the different mechanisms involved in cancer therapy and the detailed outlines of cancer drug resistance regarding multidrug resistance-associated proteins (MRPs) and their role in treatment failures by common chemotherapeutic agents. Further, different modulators of MRPs are presented. Finally, we outlined the models used to analyze MRP transporters and proposed a future impact that may set up a base or pave the way for many researchers to investigate the cancer MRP further.

Development of a Prognostic Five-Gene Signature for Diffuse Lower-Grade Glioma Patients

Background: Diffuse lower-grade gliomas (LGGs) are infiltrative and heterogeneous neoplasms. Gene signature including multiple protein-coding genes (PCGs) is widely used as a tumor marker. This study aimed to construct a multi-PCG signature to predict survival for LGG patients.

Methods: LGG data including PCG expression profiles and clinical information were downloaded from The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA). Survival analysis, receiver operating characteristic (ROC) analysis, and random survival forest algorithm (RSFVH) were used to identify the prognostic PCG signature.

Results: From the training (n = 524) and test (n = 431) datasets, a five-PCG signature which can classify LGG patients into low- or high-risk group with a significantly different overall survival (log rank P < 0.001) was screened out and validated. In terms of prognosis predictive performance, the five-PCG signature is stronger than other clinical variables and IDH mutation status. Moreover, the five-PCG signature could further divide radiotherapy patients into two different risk groups. GO and KEGG analysis found that PCGs in the prognostic five-PCG signature were mainly enriched in cell cycle, apoptosis, DNA replication pathways.

Conclusions: The new five-PCG signature is a reliable prognostic marker for LGG patients and has a good prospect in clinical application.

ABCC3 and GSTM5 gene polymorphisms affect overall survival in Polish acute myeloid leukaemia patients

Acute myeloid leukaemia (AML) is a very heterogeneous malignancy in which standard treatment is based on chemotherapy. Resistance to chemotherapeutic agents remains a big problem in AML, because negatively influences patient overall survival. Several resistance mechanisms have been described, the best of which is the process of drug removal from the cell and/or nucleus by membrane transport proteins. The aim of the study was to investigate the effect of polymorphism of genes coding ABCC3, GSTM5 involved in the transport and metabolism of drugs. For this purpose 95 newly diagnosed AML patients and 125 healthy controls were genotyped. We showed that ABCC3 rs4148405 and GSTM5 rs3754446, but not ABCC33 rs4793665, affected overall survival in Polish AML patients.

Comparative toxicity and liver transcriptomics of legacy and emerging brominated flame retardants following 5-day exposure in the rat

The relative toxicity of three legacy and six emerging brominated flame retardants* was studied in the male Harlan Sprague Dawley rat. The hepatocellular and thyroid toxicity of each flame retardant was evaluated following five-day exposure to each of the nine flame retardants (oral gavage in corn oil) at 0.1-1000 μmol/kg body weight per day. Histopathology and transcriptomic analysis were performed on the left liver lobe. Centrilobular hypertrophy of hepatocytes and increases in liver weight were seen following exposure to two legacy (PBDE-47, HBCD) and to one emerging flame retardant (HCDBCO). Total thyroxine (TT4) concentrations were reduced to the greatest extent after PBDE-47 exposure. The PBDE-47, decaBDE, and HBCD liver transcriptomes were characterized by upregulation of liver disease-related and/or metabolic transcripts. Fewer liver disease or metabolic transcript changes were detected for the other flame retardants studied (TBB, TBPH, TBBPA-DBPE, BTBPE, DBDPE, or HCDBCO). PBDE-47 exhibited the most disruption of hepatocellular toxic endpoints, with the Nrf2 antioxidant pathway transcripts upregulated to the greatest extent, although some activation of this pathway also occurred after decaBDE, HBCD, TBB, and HCBCO exposure. These studies provide information that can be used for prioritizing the need for more in-depth brominated flame retardant toxicity studies.

Pancreatic Adenocarcinoma: Unconventional Approaches for an Unconventional Disease

This review highlights current treatments, limitations, and pitfalls in the management of pancreatic cancer and discusses current research in novel targets and drug development to overcome these clinical challenges. We begin with a review of the clinical landscape of pancreatic cancer, including genetic and environmental risk factors, as well as limitations in disease diagnosis and prevention. We next discuss current treatment paradigms for pancreatic cancer and the shortcomings of targeted therapy in this disease. Targeting major driver mutations in pancreatic cancer, such as dysregulation in the KRAS and TGFβ signaling pathways, have failed to improve survival outcomes compared with nontargeted chemotherapy; thus, we describe new advances in therapy such as Ras-binding pocket inhibitors. We then review next-generation approaches in nanomedicine and drug delivery, focusing on preclinical advancements in novel optical probes, antibodies, small-molecule agents, and nucleic acids to improve surgical outcomes in resectable disease, augment current therapies, expand druggable targets, and minimize morbidity. We conclude by summarizing progress in current research, identifying areas for future exploration in drug development and nanotechnology, and discussing future prospects for management of this disease.

Inhibition of the Lysophosphatidylinositol Transporter ABCC1 Reduces Prostate Cancer Cell Growth and Sensitizes to Chemotherapy

Expression of ATP-binding cassette (ABC) transporters has long been implicated in cancer chemotherapy resistance. Increased expression of the ABCC subfamily transporters has been reported in prostate cancer, especially in androgen-resistant cases. ABCC transporters are known to efflux drugs but, recently, we have demonstrated that they can also have a more direct role in cancer progression. The pharmacological potential of targeting ABCC1, however, remained to be assessed. In this study, we investigated whether the blockade of ABCC1 affects prostate cancer cell proliferation using both in vitro and in vivo models. Our data demonstrate that pharmacological inhibition of ABCC1 reduced prostate cancer cell growth in vitro and potentiated the effects of Docetaxel in vitro and in mouse models of prostate cancer in vivo. Collectively, these data identify ABCC1 as a novel and promising target in prostate cancer therapy.

Bioactive lipids in cancer stem cells

Tumours are known to be a heterogeneous group of cells, which is why they are difficult to eradicate. One possible cause for this is the existence of slow-cycling cancer stem cells (CSCs) endowed with stem cell-like properties of self-renewal, which are responsible for resistance to chemotherapy and radiotherapy. In recent years, the role of lipid metabolism has garnered increasing attention in cancer. Specifically, the key roles of enzymes such as stearoyl-CoA desaturase-1 and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase in CSCs, have gained particular interest. However, despite accumulating evidence on the role of proteins in controlling lipid metabolism, very little is known about the specific role played by lipid products in CSCs. This review highlights recent findings on the role of lipid metabolism in CSCs, focusing on the specific mechanism by which bioactive lipids regulate the fate of CSCs and their involvement in signal transduction pathways.

Pharmacological inhibition of ABCC3 slows tumour progression in animal models of pancreatic cancer

Background

Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive and lethal disease, lacking effective therapeutic approaches. Available therapies only marginally prolong patient survival and are frequently coupled with severe adverse events. It is therefore pivotal to investigate novel and safe pharmacological approaches. We have recently identified the ABC transporter, ABCC3, whose expression is dependent on mutation of TP53, as a novel target in PDAC. ABCC3-mediated regulation of PDAC cell proliferation and tumour growth in vivo was demonstrated and was shown to be conferred by upregulation of STAT3 signalling and regulation of apoptosis.

Methods

To verify the potential of ABCC3 as a pharmacological target, a small molecule inhibitor of ABCC3, referred to here as MCI-715, was designed. In vitro assays were performed to assess the effects of ABCC3 inhibition on anchorage-dependent and anchorage-independent PDAC cell growth. The impact of ABCC3 inhibition on specific signalling pathways was verified by Western blotting. The potential of targeting ABCC3 with MCI-715 to counteract PDAC progression was additionally tested in several animal models of PDAC, including xenograft mouse models and transgenic mouse model of PDAC.

Results

Using both mouse models and human cell lines of PDAC, we show that the pharmacological inhibition of ABCC3 significantly decreased PDAC cell proliferation and clonal expansion in vitro and in vivo, remarkably slowing tumour growth in mice xenografts and patient-derived xenografts and increasing the survival rate in a transgenic mouse model. Furthermore, we show that stromal cells in pancreatic tumours, which actively participate in PDAC progression, are enriched for ABCC3, and that its inhibition may contribute to stroma reprogramming.

Conclusions

Our results indicate that ABCC3 inhibition with MCI-715 demonstrated strong antitumor activity and is well tolerated, which leads us to conclude that ABCC3 inhibition is a novel and promising therapeutic strategy for a considerable cohort of patients with pancreatic cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1308-7) contains supplementary material, which is available to authorized users.