Expression Of ABC Transporter Genes Research Articles

MiR-128-3p suppresses tumor growth and enhances chemosensitivity in tongue squamous cell carcinoma through MAP2K7 targeting.

MicroRNAs (miRNAs), which are key players in cancer cell resistance to chemotherapy, notably target genes associated with drug resistance. While miRNA-128-3p is recognized for its involvement in various cancers, its specific role in tumorigenesis and cisplatin (CIS) resistance in tongue cancer remains unclear. Therefore, in the present study, we endeavoured to elucidate the significance of miR-128-3p in tongue squamous cell carcinoma (TSCC), shedding light on its intricate functions and underlying mechanisms. We quantified the expression of miR-128-3p and its target genes using qRT-PCR, followed by a series of functional assays in vitro, such as proliferation and migration assays, flow cytometry analysis, and western blotting to unravel the mechanisms underlying the functions of miR-128-3p. Additionally, we validated the ability of miR-128-3p to target MAP2K7 genes through luciferase reporter assays. We observed that increased expression of miR-128-3p significantly inhibited TSCC cell migration, proliferation, and epithelial-mesenchymal transition (EMT), possibly by regulating MAP2K7 in the JNK/MAP kinase pathway through miRNA target binding. Furthermore, we showed that increased miR-128-3p levels enhanced the sensitivity of TSCC cells to CIS through the JNK/c-Jun cascade. We observed that miR-128-3p reduces the expression of c-Jun and ABC transporter genes by targeting MAP2K7, affecting JNK1/2. This inhibition possibly decreases drug efflux and thus enhances the TSCC sensitivity to CIS treatment. Our findings demonstrate oncosuppressive behaviour of miR-128-3p, which also potentially enhances the sensitivity of TSCC cells to CIS by suppressing MAP2K7 and JNK1/2, leading to evasion of apoptosis.

The response mechanism of alkalophilic Nitzschia sp. NW129 to low alkalinity-A study combining physiological and transcriptional analysis

Global aquatic acidification significantly threatens alkaline lake ecosystems. The mechanisms by which alkaliphilic microalgae, the key producers in these ecosystems, respond to reduced environmental alkalinity remain poorly understood. Here, we investigated the responses of alkalophilic Nitzschia sp. NW129 to low alkalinity (pH 9.2) through integrated physiological-biochemical and transcriptomic analyses. Relative to the control (pH 11.5), we observed a 60.1 % decrease in polysaccharide content, while total lipids and proteins increased by 1.74-fold and 2-fold, respectively. Transcriptome analysis revealed up-regulation of genes encoding carbonic anhydrase (CA) and malic enzyme (ME), along with those involved in glycolysis and fatty acid (FA) synthesis, compensating for carbon supply and shifting carbon flux from carbohydrate synthesis to lipid accumulation. Enhanced expression of TCA cycle genes and those encoding F-ATP synthase and inorganic pyrophosphatase (PPase) provided sufficient energy for cellular homeostasis, further facilitated by the up-regulated expression of ATP-dependent V-ATPase and ABC transporter genes. Temporal analysis revealed that the expression of genes involved in protein synthesis pathways was up-regulated on days 1 and 4 but notably down-regulated on day 2, suggesting protein degradation at this time to balance energy supply for adaptation. Despite these coping shifts, impairments in photosynthetic energy dissipation and electron transport, along with transcriptional changes including down-regulating cell cycle and inducing apoptotic pathways, ultimately caused a substantial reduction in biomass. These findings provide a basic understanding of the response mechanisms of alkalophilic microalgae to low alkalinity stress, which should aid to develop strategies to improve microalgal tolerance against acidification.

Influence of Human Bone Marrow Mesenchymal Stem Cells Secretome from Acute Myeloid Leukemia Patients on the Proliferation and Death of K562 and K562-Lucena Leukemia Cell Lineages.

Leukemias are among the most prevalent types of cancer worldwide. Bone marrow mesenchymal stem cells (MSCs) participate in the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases such as leukemias, to a yet unknown extent. Here we described the effect of secretome of bone marrow MSCs obtained from healthy donors and from patients with acute myeloid leukemia (AML) on leukemic cell lineages, sensitive (K562) or resistant (K562-Lucena) to chemotherapy drugs. Cell proliferation, viability and death were evaluated, together with cell cycle, cytokine production and gene expression of ABC transporters and cyclins. The secretome of healthy MSCs decreased proliferation and viability of both K562 and K562-Lucena cells; moreover, an increase in apoptosis and necrosis rates was observed, together with the activation of caspase 3/7, cell cycle arrest in G0/G1 phase and changes in expression of several ABC proteins and cyclins D1 and D2. These effects were not observed using the secretome of MSCs derived from AML patients. In conclusion, the secretome of healthy MSCs have the capacity to inhibit the development of leukemia cells, at least in the studied conditions. However, MSCs from AML patients seem to have lost this capacity, and could therefore contribute to the development of leukemia.

Altered Gene Expression of Cytochrome P450 and ABC Transporter in Human Hepatocellular Carcinoma HepG2 Cells Exposed to Bardoxolone Methyl.

Bardoxolone methyl (BX) is expected to be an innovate therapeutic agent for chronic kidney disease (CKD). The aim of the present study was to examine whether the expression of subtypes of cytochrome P450 (CYP) and ABC transporters was altered in human hepatocellular carcinoma HepG2 cells by exposure to BX. The expression of mRNAs for CYP1A2, CYP2E1, P-glycoprotein, multidrug resistance-associated protein 1-3, and breast cancer resistance protein was significantly increased by exposure of HepG2 cells to BX, while the expression of CYP3A4 mRNA was significantly decreased under the same conditions. BX had no significant effect on the expression of mRNAs for CYP2C9 and CYP2C19 in HepG2 cells. In conclusion, this study demonstrated that the gene expression of several CYPs and ABC transporters in HepG2 cells was altered when exposed to BX, suggesting the need to pay careful attention to drug-drug interactions in patients receiving BX for CKD treatment.

The Molecular Mechanisms of Oleanane Aldehyde-β-enone Cytotoxicity against Doxorubicin-Resistant Cancer Cells.

Oleanane aldehyde-β-enone (OA), being the semi-synthetic derivative of the triterpenoid betulin, effectively inhibits the proliferation of HBL-100 and K562 cancer cells (IC50 0.47-0.53 µM), as well as the proliferation of their resistant subclones with high P-gp expression HBL-100/Dox, K562/i-S9 and K562/i-S9_Dox (IC50 0.45-1.24 µM). A molecular docking study, rhodamine efflux test, synergistic test with Dox, and ABC transporter gene expression were used to investigate the ability of OA to act as a P-gp substrate or inhibitor against Dox-resistant cells. We noted a trend toward a decrease in ABCB1, ABCC1 and ABCG2 expression in HBL-100 cells treated with OA. The in silico and in vitro methods suggested that OA is neither a direct inhibitor nor a competitive substrate of P-gp in overexpressing P-gp cancer cells. Thus, OA is able to overcome cellular resistance and can accumulate in Dox-resistant cells to realize toxic effects. The set of experiments suggested that OA toxic action can be attributed to activating intrinsic/extrinsic or only intrinsic apoptosis pathways in Dox-sensitive and Dox-resistant cancer cells, respectively. The cytotoxicity of OA in resistant cells is likely mediated by a mitochondrial cell death pathway, as demonstrated by positive staining with Annexin V-FITC, an increasing number of cells in the subG0/G1 phase, reactive oxygen species generation, mitochondrial dysfunction, cytochrome c migration and caspases-9,-6 activation.

Expression heterogeneity of ABC-transporter family genes and chemosensitivity genes in gastric tumor, carcinomatosis and lymph node metastases

Introduction. Metastatic tumors (particularly gastric cancer) have been found to be characterized by heterogeneity between the primary tumor and metastases. This type of heterogeneity comes to the fore when treating primary-metastatic forms of tumor and is an important reason for the low effectiveness of their treatment. In this regard, comparative analysis of ABC-transporter gene expression and chemosensitivity genes will allow to characterize to a certain extent the resistance and sensitivity of primary tumor, carcinomatosis and metastases to therapy and provide the basis for personalized treatment approach.Aim. To evaluate expression heterogeneity of ABC-transporter genes and chemosensitivity genes in gastric tumor, carcinomatosis and lymph node metastases.Materials and methods. Overall 41 patients with disseminated gastric cancer stage IV with carcinomatosis of peritoneum were included in the investigation. All patients underwent surgery according to Roux palliative gastrectomy. After surgery patients underwent chemotherapy depending on indications. RNA was isolated using RNeasy Plus mini kit (Qiagen, Germany). The expression level of ABC transporter genes (ABCB1, ABCC1, ABCC2, ABCC5, ABCG1, ABCG2) and chemosensitivity genes (BRCA1, RRM1, ERCC1, TOP1, TOP2α, TUBβ3, TYMS, GSTP1) was assessed by reverse transcription polymerase chain reaction (RT-PCR) in primary tumor, carcinomatosis and lymph node metastases.Results. The expression levels of the genes under study were shown to vary widely. For ABC transporter genes, ABCG1 (3.1 ± 1.1; max 32.0), ABCG2 (7.9 ± 2.3; max 54.1), ABCG2 (9.6 ± 3.8; max 101.0) were the most expressed genes in gastric tumor tissue, carcinomatosis and lymph node metastasis, respectively. Hyperexpression among chemosensitivity genes at all three sites was characteristic only of TOP2α (17.2 ± 6.0; max. 161.9; 10.8 ± 4.1; max. 105.1; 35.3 ± 0.8; max. 439.6, respectively). We found that TOP2α and BRCA1 gene expression levels were higher in lymph node metastasis compared with gastric tumor tissue and carcinomatosis (at p = 0.005 and p = 0.001). Whereas ABCC1 gene expression was statistically significantly higher in carcinomatosis (p = 0.03).Conclusion. Thus, a high level of expression heterogeneity is observed in gastric cancer, which affects the expression patterns of various genes in different localizations. The expression profile can be used to determine the level of heterogeneity and approach to personalized therapy tactics.

Prognostic and Predictive Significance of mRNA Expression of ABC-transporter Genes in Patients with Non-small Cell Lung Cancer

Introduction. To date, one of the reasons for the ineffectiveness of chemotherapy in various malignant neoplasms, including lung cancer, is the formation of the multidrug resistance (MDR) phenotype in tumor cells, which is caused by the expression of ABC transporter genes.Aim. The aim of this work was to assess the expression of ABC-transporter genes during chemotherapy and to analyze the relationship with the effectiveness of chemotherapy and prognosis of the disease.Materials and methods. We used biopsy and surgical material from 91 patients with stage IIB–IIIA non-small cell lung cancer (NSCLC). The treatment regimen included: 2 courses of neoadjuvant chemotherapy (NAC), surgery and 3 courses of adjuvant chemotherapy (ACT) with platinum doublets. RNA was isolated from the samples, followed by quantitative PCR to assess the expression of genes ABCB1, ABCC1, ABCC2, ABCC5, ABCG1, ABCG2.Results and discussion. It was shown that the level of expression of the studied genes was not associated with the effect of NAC in patients with lung cancer, except for the ABCC5 gene, which showed a relationship at the level of a pronounced trend (p = 0.07). It was also shown that in the group of patients with an objective response to chemotherapy, the frequency of decreased expression of the ABCC1 (p = 0.01) and ABCC5 (p = 0.004) genes was statistically significantly higher than in the group of patients with stabilization. Further, using the Kaplan – Meier method, it was found that a decrease in expression is associated with high rates of metastatic-free survival (MFS). The highest rates of 5-year MFS (more than 85 %) are observed in patients with a decrease in the expression of the ABCB1 and ABCG2 genes, log-rank test p = 0.0007 and p = 0.002, respectively.Conclusion. Thus, it has been shown that changes in the expression of ABC transporter genes are associated with the effectiveness of chemotherapy and the prognosis of the disease. The data obtained can be used as a basis for the detection of potential drug targets.

P113 Expression profile of ABC and MFS multi-drug transporter genes in terbinafine- and fluconazole-resistant Trichophyton spp.

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectivesOver the past few decades, an unprecedented increase in recalcitrant and chronic dermatophytosis with atypical clinical presentations have been noted in the Indian subcontinent. Recent studies have reported Trichophyton mentagrophytes/interdigitale complex as predominant etiological agent of chronic/recurrent dermatophytosis followed by T. rubrum. Multiple factors, including unregulated use of antifungal drugs, poor compliance to treatment, and irrational fixed-drug combinations are associated with emerging resistance. However, molecular studies investigating the underlying mechanisms related to terbinafine and fluconazole resistance in dermatophytes are sparse.The present study was designed to explore the role of multidrug efflux transporters in terbinafine- and fluconazole-resistant T. mentagrophytes/interdigitale complex and T. rubrum.MethodsThe expression of MDR transporter genes was evaluated in 36 isolates with terbinafine resistance (with or without F397L or L393F mutation in squalene epoxidase gene, SE) of T. mentagrophytes/interdigitale complex (n = 26), and T. rubrum (n = 10) isolates along with 16 susceptible wild-type isolates of T. mentagrophytes/interdigitale complex (n = 10), and T. rubrum (n = 6) isolates. In addition, 19 fluconazole-resistant T. mentagrophytes/interdigitale complex (n = 11), and T. rubrum (n = 8) isolates along with 13 susceptible T. mentagrophytes/interdigitale complex (n = 9), and T. rubrum (n = 4) were also included. Quantitative real-time PCR (qRT-PCR) was used to evaluate the expression of ABC transporter (MDR1, MDR2, MDR3, MDR4, and MDR5) and MFS transporter genes (MFS1 and MFS2).ResultsIn terbinafine-resistant T. mentagrophytes/interdigitale complex, the mean expression of MDR1 and MDR2 was 4.98 and 5.27-fold in isolates with wild-type SE, compared with 0.64 and 1.04-fold in isolates with non-wildtype SE gene (P <.0001) and susceptible isolates at 0.4, and 0.88-fold (P <.0001), respectively. For MFS1 gene, 3.4-fold-change expression was noted in isolates with wild-type SE compared with 1.51-fold in isolates with non-wild type SE (P <.001). In resistant isolates with non-WT SE, the upregulation of the SE gene was noted at 6.3-fold compared with 1.8-fold in isolates with wild-type SE (P <.001), and 0.63-fold in susceptible isolates (P <.0001). However, there was no significant upregulation of MDR3, MDR4, MDR5, and MFS2 genes among the three groups. In terbinafine-resistant T. rubrum, the mean inducible expression of MDR1 was significantly higher in isolates with wild-type SE at 3.88-fold compared to isolates with non-wild type SE at 0.5-fold (P <.05) and susceptible isolates at 0.33-fold (P <.01). Only resistant isolates with wild-type SE showed significant up-regulation of MDR2 (P <.01) compared to susceptible isolates. Other genes, MDR3, MDR4, MDR5, MFS1, MFS2, and SE, did not show substantial overexpression among the groups (Resistant WT vs. Resistant NWT vs. susceptible WT). In fluconazole-resistant and -susceptible isolates of T. mentagrophytes/interdigitale complex, and T. rubrum, similar findings were observed. In both the species, the mean inducible expression of MDR1, MDR2, and MDR3 was significantly higher (P <.05) in resistant isolates compared to susceptible isolates.ConclusionIn conclusion, this study demonstrates the overexpression of MDR1 and MDR2 in terbinafine-resistant Trichophyton spp. isolates lacking drug-target gene mutation, suggesting the role of multidrug transporters in resistance. This study also suggests the importance of MDR2, and MDR3 transporter genes in imparting fluconazole resistance in Trichophyton spp.

Pyrethroid insecticide and milkweed cardenolide interactions on detoxification enzyme activity and expression in monarch caterpillars

Declines of the monarch butterfly population have prompted large-scale plantings of milkweed to restore the population. In North America, there are >73 species of milkweed to choose from for these nationwide plantings. However, it is unclear how different milkweed species affect monarch caterpillar physiology, particularly detoxification enzyme activity and gene expression, given the highly variable cardenolide composition across milkweed species. Here, we investigate the effects of a high cardenolide, tropical milkweed species and a low cardenolide, swamp milkweed species on pyrethroid sensitivity as well as detoxification enzyme activity and expression in monarch caterpillars. Caterpillars fed on each species through the fifth-instar stage and were topically treated with bifenthrin after reaching this final-instar stage. Esterase, glutathione S-transferase, and cytochrome P450 monooxygenase activities were quantified as well as the expression of selected esterase, glutathione S-transferase, ABC transporter, and cytochrome P450 monooxygenase transcripts. There were no significant differences in survival 24 h after treatment with bifenthrin. However, bifenthrin significantly increased glutathione S-transferase activity in caterpillars feeding on tropical milkweed and significantly decreased esterase activity in caterpillars feeding on tropical and swamp milkweed. Significant differential expression of ABC transporter, glutathione S-transferase, and esterase genes was observed for caterpillars feeding on tropical and swamp milkweed and not receiving bifenthrin treatment. Furthermore, significant differential expression of glutathione S-transferase and esterase genes was observed for bifenthrin-treated and -untreated caterpillars feeding on tropical milkweed relative to swamp milkweed. These results suggest that feeding on different milkweed species can affect detoxification and development mechanisms with which monarch caterpillars rely on to cope with their environment.

Abstract 2620: Combination of growth hormone receptor antagonist and gemcitabine leads to highly efficacious tumor clearance in a mouse model of pancreatic ductal adenocarcinoma

Abstract Pancreatic cancer is responsible for more than 48,000 deaths and 60,000 new cancer cases every year in the United States while the overall 5-year survival rate is only 10%. These numbers point towards an urgent need for new therapeutic approaches wherein therapy resistance poses a tremendous challenge. We and others have identified the role of growth hormone (GH) and its cognate receptor (GHR), overexpressed in pancreatic ductal adenocarcinoma patients (PDAC; &amp;gt;90% of pancreatic cancer cases), in driving therapy resistance by directly upregulating multidrug efflux, phenotype switch via epithelial-to-mesenchymal transition (EMT) and inhibition of apoptosis. Our laboratory had pioneered the discovery of pharmacologic GHR antagonists including the only approved and prescribed GHR antagonist, pegvisomant, and a new antagonist candidate named compound-G. Here, we used in vitro, in vivo and in silico analyses to assess the feasibility and efficacy of a treatment regimen including GHR antagonist and chemotherapy to manage PDAC. Both pegvisomant and compound-G exhibit significant suppression of cancer cellular viability, invasive potential, drug efflux rate and apoptosis in PDAC cell cultures. In male and female Nude mice with human PDAC xenografts, GHR inhibition by either pegvisomant or compound-G markedly re-sensitized the tumors towards both low and high doses of gemcitabine treatment. Compound G plus high doses of gemcitabine lead to almost complete tumor clearance in 40% of the mice. Also, tissue analyses reveal increased production of GH in tumors treated with chemotherapy. In the GHR antagonist treated tumors, significantly lower expression of ABC transporter (Abcb1, Abcg5, Abcc2, Abcg2), EMT mediator (Cdh2, Zeb1, Snai2, Epas1) and apoptosis marker (Bcl2) genes compared to control were observed - accounting for the observed sensitization to gemcitabine. In the human PDAC patient datasets, increased expression of GHR correlates strongly with increased expression of multidrug efflux transporters, anti-apoptotic markers, and EMT transcription factors. Therefore, we provide robust pre-clinical validation for a treatment regimen combining GHR antagonist and chemotherapy leading to highly efficacious tumor clearance. Acknowledgement: This work was supported in part by the State of Ohio’s Eminent Scholar Program that includes a gift from Milton and Lawrence Goll, by the AMVETS, and Ohio University’s Student Enhancement Award and Edison Biotechnology Institute. Citation Format: Reetobrata Basu, Prateek Kulkarni, Emily Davis, Silvana Duran, John J. Kopchick. Combination of growth hormone receptor antagonist and gemcitabine leads to highly efficacious tumor clearance in a mouse model of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2620.

DNA Copy Number Aberrations and Expression of ABC Transporter Genes in Breast Tumour: Correlation with the Effect of Neoadjuvant Chemotherapy and Prognosis of the Disease

One of the important reasons for the ineffectiveness of chemotherapy in breast cancer (BC) is considered to be the formation of a multidrug resistance phenotype in tumour cells, which is caused by the expression of energy-dependent ABC transporters. The aim of this work was to assess chromosomal aberrations and the level of transcripts of all 49 known ABC transporter genes in breast tumours. Materials and Methods. The study included 129 patients with breast cancer. A microarray study of all tumour samples was carried out on microchips. Results. This study established that the presence of a deletion in genes ABCB1, ABCB4, ABCB8, ABCC7, ABCC11, ABCC12, ABCF2, and ABCG4 is associated with an objective response to treatment (p ≤ 0.05). A decrease in the expression of genes was associated with a good response to chemotherapy, whereas an increase in expression caused the progression and stabilization of the tumour. Analysis of metastatic-free survival rates showed that the presence of ABCB1/4 and ABCC1/6 deletions was associated with 100% survival (log-rank test p = 0.01 and p = 0.03). Conclusions. The study showed that the aberrant state of ABC transporter genes, as well as a decrease in the expression of these genes, is a predictor of the effectiveness of therapeutic treatment and a potential prognostic marker of metastatic survival.

Analysis of ABC Transporter Gene Expression in Atherosclerosis

ABC transporters are a large family of membrane proteins that transport chemically diverse substrates across the cell membrane. Disruption of transport mechanisms mediated by ABC transporters causes the development of various diseases, including atherosclerosis. Methods: A bioinformatic analysis of a dataset from Gene Expression Omnibus (GEO) was performed. A GEO dataset containing data on gene expression levels in samples of atherosclerotic lesions and control arteries without atherosclerotic lesions from carotid, femoral, and infrapopliteal arteries was used for analysis. To evaluate differentially expressed genes, a bioinformatic analysis was performed in comparison groups using the limma package in R (v. 4.0.2) and the GEO2R and Phantasus tools (v. 1.11.0). Results: The obtained data indicate the differential expression of many ABC transporters belonging to different subfamilies. The differential expressions of ABC transporter genes involved in lipid transport, mechanisms of multidrug resistance, and mechanisms of ion exchange are shown. Differences in the expression of transporters in tissue samples from different arteries are established. Conclusions: The expression of ABC transporter genes demonstrates differences in atherosclerotic samples and normal arteries, which may indicate the involvement of transporters in the pathogenesis of atherosclerosis.

Triterpenoids with modified A-ring as modulators of P-gp-dependent drug-resistance in cancer cells

Semi-synthetic A-cycle modified triterpenic derivatives with A-cycle condensed with a heterocyclic fragment (compound 1) and fragmented A-ring (compound 2) were tested for cytotoxicity against several tumor cell cultures and doxorubicin (Dox)-resistant cell lines. The equal cytotoxicity of the tested compounds to the parental tumor cell lines (HBL-100, K562) and their resistant subclones (HBL-100/Dox, K562/i-S9) was revealed. The overexpression of ABCB1 (MDR1) gene and P-glycoprotein (P-gp) was confirmed for both resistant subclones of tumor cells. Compounds 1 and 2 were shown to inhibit the ABC-transporter gene expression (MDR1, MRP, MVP, and BCRP) and the transport of well-known P-gp substrate Rhodamine 123 from resistant cells. The docking of triterpenoids 1 and 2 into the drug binding site of P-gp revealed a similarity between the conformation of the tested triterpenoids and that of classical inhibitor verapamil, thus assuming these compounds to be more likely the inhibitors than the substrates of P-gp. Any tested triterpenic derivatives, when combined at non-toxic concentrations with doxorubicin, improved cytotoxic effect of the therapeutic drug against resistant subclones of tumor cells.

Delineating the Role of Aedes aegypti ABC Transporter Gene Family during Mosquito Development and Arboviral Infection via Transcriptome Analyses.

Aedes aegypti acts as a vector for several arboviral diseases that impose a major socio-economic burden. Moreover, the absence of a vaccine against these diseases and drug resistance in mosquitoes necessitates the development of new control strategies for vector-borne diseases. ABC transporters that play a vital role in immunity and other cellular processes in different organisms may act as non-canonical immune molecules against arboviruses, however, their role in mosquito immunity remains unexplored. This study comprehensively analyzed various genetic features of putative ABC transporters and classified them into A-H subfamilies based on their evolutionary relationships. Existing RNA-sequencing data analysis indicated higher expression of cytosolic ABC transporter genes (E & F Subfamily) throughout the mosquito development, while members of other subfamilies exhibited tissue and time-specific expression. Furthermore, comparative gene expression analysis from the microarray dataset of mosquito infected with dengue, yellow fever and West Nile viruses revealed 31 commonly expressed ABC transporters suggesting a potentially conserved transcriptomic signature of arboviral infection. Among these, only a few transporters of ABCA, ABCC and ABCF subfamily were upregulated, while most were downregulated. This indicates the possible involvement of ABC transporters in mosquito immunity.

Gibberellic acid-induced fatty acid metabolism and ABC transporters promote astaxanthin production in Phaffia rhodozyma.

Astaxanthin is an important natural antioxidant with various biological functions; however, the production of astaxanthin does not meet the requirements for industrialization. The aim of the present study was to identify an inducer that increases astaxanthin yield and to evaluate the regulatory mechanism of the induction of astaxanthin synthesis in Phaffia rhodozyma. The effects of indole-3-acetic acid (IAA), jasmonic acid (JA) and gibberellic acid (GA) on astaxanthin synthesis were studied by fermentation kinetics analysis. Then, combined transcriptomics and metabolomics approaches were used to analyse differential metabolites and expressed genes involved in astaxanthin synthesis induced by GA. The results indicated that GA significantly increased astaxanthin production; however, IAA and JA had no significant effect on astaxanthin synthesis. The induction by GA significantly enhanced fatty acid metabolism and ABC transporters, increased the expression of fatty acid desaturase and ABC transporter genes, and elevated the contents of unsaturated fatty acids. These results suggested that fatty acid saturation plays an important role in astaxanthin accumulation and that ABC transporters may be the efflux pumps for astaxanthin. The present study reveals metabolic mechanism of GA-induced astaxanthin synthesis and proposes a new strategy of transporter engineering to improve astaxanthin production.

Metagenomic and metatranscriptomic profiling of Lactobacillus casei Zhang in the human gut

Little is known about the replication and dynamic transcription of probiotics during their “passenger” journey in the human GI tract, which has therefore limited the understanding of their probiotic mechanisms. Here, metagenomic and metatranscriptomic sequencing was used to expose the in vivo expression patterns of the probiotic Lactobacillus casei Zhang (LcZ), which was compared with its in vitro growth transcriptomes, as well as the dynamics of the indigenous microbiome response to probiotic consumption. Extraction of the strain-specific reads revealed that replication and transcripts from the ingested LcZ were increased, while those from the resident L. casei strains remained unchanged. Mapping of all sequencing reads to LcZ genome showed that gene expression in vitro and in vivo differed dramatically. Approximately 39% of mRNAs and 45% of sRNAs of LcZ well-expressed were repressed after ingestion into human gut. The expression of ABC transporter genes and amino acid metabolism genes was induced at day 14 of ingestion, and genes for sugar and SCFA metabolism were activated at day 28 of ingestion. Expression of rli28c sRNA with peaked expression during the in vitro stationary phase was also activated in the human gut; this sRNA repressed LcZ growth and lactic acid production in vitro. However, the response of the human gut microbiome to LcZ was limited and heterogeneous. These findings implicate the ingested probiotic has to change its transcription patterns to survive and adapt in the human gut, and the time-dependent activation patterns indicate highly dynamic cross-talk between the probiotic and human gut microbes.

Transcriptional regulation of alcohol induced liver fibrosis in a translational porcine hepatocellular carcinoma model

Hepatocellular carcinoma (HCC) is the 5th most common and 2nd deadliest cancer worldwide. HCC risk factors include alcohol induced liver cirrhosis, which prompts hepatic inflammation, cell necrosis, and fibrosis deposition. As 25% of HCC cases are associated with alcohol induced liver disease, understanding the effects of the cirrhotic liver microenvironment on HCC tumor biology and therapeutic responses are critical. This study utilized the Oncopig Cancer Model—a transgenic pig model that recapitulates human HCC through induced expression of KRASG12D and TP53R167H driver mutations—to investigate the molecular mechanisms underlying alcohol induced liver disease. Oncopigs (n = 5) underwent fibrosis induction via infusion of ethanol and ethiodized oil (1:3 v/v dosed at 0.75 mL/kg) into the hepatic arterial circulation. Eight-weeks post induction, liver tissue samples from fibrotic and age-matched control (n = 5) Oncopigs were collected for histological evaluation and transcriptional profiling. Increased hepatic inflammation and fibrosis was observed in fibrotic Oncopigs via pathological assessment. Transcriptional profiling (RNA-seq) resulted in the identification of 4387 differentially expressed genes between Oncopig fibrotic and control livers. GO term enrichment analysis identified pathway alterations associated with cirrhosis progression in humans, including cell proliferation, angiogenesis, extracellular matrix deposition, and oxidation-reduction. Key alterations include activation of hepatic stellate cells, increased matrix metalloproteinase production, and altered expression of ABC and SLC transporter genes involved in transport of anticancer drugs.These results demonstrate Oncopig liver fibrosis recapitulates transcriptional hallmarks of human cirrhosis, making the Oncopig an ideal model for studying the effects of the cirrhotic liver microenvironment on HCC tumor biology and therapeutic response.

The comparative toxicity of rainfall overflows and a municipal effluent plume in Elliptio complanata using a novel qPCR array approach

Municipal effluents have the potential to disrupt the endocrine system involved in reproduction in aquatic organisms. The purpose of this study was to develop a novel a quantitative polymerase chain reaction (qPCR) array for the freshwater mussel Elliptio complanata to compare the toxic properties of municipal effluents and rainfall overflows. Mussels were caged for 3 months at upstream and downstream sites of a municipal effluent discharge point and 2 rainfall overflow sites in the Saint-Lawrence River. The data revealed that exposure to municipal effluents and overflow sites lead to increased expression of vitellogenin (VTG) in male mussels, altered sexual differentiation in females, gene expression involved in oxidative stress (superoxide dismutase, glutathione S-transferase) and DNA damage (chromosome mismatch and repair of covalently-bound DNA adducts). Mussels at the downstream site accumulated also large amounts of heterotrophic bacteria but not at the overflow sites. However, mussels at the overflow sites had decreased expression in ABC transporter gene expression. Scaling analysis revealed that the following gene expression were related to effects at higher level of biological organization such as total RNA levels, gonad mass and gonad somatic index: DNA repair of covalent DNA adducts, mistmach chromosomal recombination during meiosis and undifferentiated cells in gonads. In conclusion, exposure to rainfall overflow sites have similar effects to municipal effluents based on VTG and oxidative stress responses at the transcriptomic levels only but the effects at the DNA integrity and sexual differentiation were involved in adverse outcome pathways of urban pollution in Elliptio complanata mussels.

An integrated epigenome and transcriptome analysis identifies PAX2 as a master regulator of drug resistance in high grade pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is notoriously difficult to treat due to its aggressive, ever resilient nature. A major drawback lies in its tumor grade; a phenomenon observed across various carcinomas, where highly differentiated and undifferentiated tumor grades, termed as low and high grade respectively, are found in the same tumor. One eminent problem due to such heterogeneity is drug resistance in PDAC. This has been implicated to ABC transporter family of proteins that are upregulated in PDAC patients. However, the regulation of these transporters with respect to tumor grade in PDAC is not well understood. To combat these issues, a study was designed to identify novel genes that might regulate drug resistance phenotype and be used as targets. By integrating epigenome with transcriptome data, several genes were identified based around high grade PDAC. Further analysis indicated oncogenic PAX2 transcription factor as a novel regulator of drug resistance in high grade PDAC cell lines. It was observed that silencing of PAX2 resulted in increased susceptibility of high grade PDAC cells to various chemotherapeutic drugs. Mechanistically, the study showed that PAX2 protein can bind and alter transcriptionally; expression of many ABC transporter genes in high grade PDAC cell lines. Overall, the study indicated that PAX2 significantly upregulated ABC family of genes resulting in drug resistance and poor survival in PDAC.

Differential ABC transporter gene expression in adult Dirofilaria immitis males and females following in vitro treatment with ivermectin, doxycycline or a combination of both

BackgroundCombination doxycycline/macrocyclic lactone (ML) protocols have been shown to provide a more rapid adulticidal and microfilaricidal effect than either MLs or doxycycline alone, although female worms were reported to have a higher tolerance to treatments compared to male worms. The present study aimed to evaluate how ABC transporters may be involved in the synergic effect of the combination treatment. Adult worms of D. immitis were treated in vitro for 24 hours with doxycycline (DOXY), ivermectin (IVM) and a combination of both, and changes in the modulation of ABC transporter genes were measured. Levels of doxycycline inside different treatment media, post-treatment, were determined through HPLC analysis.ResultsQuantitative RT-PCR analysis showed the presence of changes in the modulation of ABC transporter genes evaluated in this study. In particular, in female worms, the combination treatment induced a substantial increase in gene expressions, especially of Dim-pgp-10 and Dim-haf-4; whereas in male worms, the greatest increase in gene expression was observed for Dim-pgp-10 and Dim-pgp-11 when treated with DMSO + IVM and DMSO + DOXY/IVM. HPLC analysis of the DOXY concentrations in the media after in vitro treatments of male worms showed a slight difference between the DMSO + DOXY samples and the combination (DMSO + DOXY + IVM), while no difference was observed among females.ConclusionsFurther studies are required to explain whether the modulation of cellular efflux plays a role, even partially, in the adulticide effect of doxycycline/macrocyclic lactone combinations in heartworm-infected dogs. To the authors’ knowledge, this is the first study to evaluate P-gp expression in adult D. immitis.