Resistance Protein Research Articles

Structure of a dimeric full-length ABC transporter.

Activities of ATP binding cassette (ABC) proteins are regulated by multiple mechanisms, including protein interactions, phosphorylation, proteolytic processing, and/or oligomerization of the ABC protein itself. Here we present the structure of yeast cadmium factor 1 (Ycf1p) in its mature form following cleavage by Pep4p protease. Ycf1p, a C subfamily ABC protein (ABCC), is homologue of human multidrug resistance protein 1. Remarkably, a portion of cleaved Ycf1p forms a well-ordered dimer, alongside monomeric particles also present in solution. While numerous other ABC proteins have been proposed to dimerize, no high-resolution structures have been reported. Both phosphorylation of the regulatory (R) region and ATPase activity are lower in the Ycf1p dimer compared to the monomer, indicating that dimerization affects Ycf1p function. The interface between Ycf1p protomers features protein-protein interactions and contains bound lipids, suggesting that lipids stabilize the dimer. The Ycf1p dimer structure may inform the dimerization interfaces of other ABCC dimers.

Towards streamlined product information: reporting of transporter-mediated drug interactions.

The purpose of this study is to investigate the reporting of risks associated with transporter-mediated drug-drug interactions (DDIs) in medicinal product information and to identify suitable wording for future standardisation of summaries of product characteristics (SmPCs). The SmPCs of medicinal products approved in the European Union from 2012 to 2023 were screened for warnings on Organic Anion Transporting Polypeptide 1B1 and 1B3 (OATP1B1 and OATP1B3), and Breast Cancer Resistance Protein (BCRP). An in-house search engine for product information was used. Warnings were categorised into different DDI scenarios based on the SmPC texts. A total of 192 out of 859 approved medicinal products had SmPC text pertaining to OATP1B1, 1B3 and/or BCRP. The majority of products had text for all three transporters Most texts were located in SmPC Sect.5.2, followed bySect. 4.5. Numerous interaction-texts either concluded that the interaction lacked clinical relevance or lacked information on the clinical relevance of the finding. The highest number of SmPC texts indicating a clinically relevant interaction with outlined clinical consequences was found for BCRP. The article also presents SmPC texts for each DDI scenario, which the authors consider as examples of explicitwordings with actionable recommendations. A potential for improvement of SmPC text for transporter-mediated DDI was identified: Warnings without clinical relevance could be omitted, and some warnings with clinical relevance could be updated to provide actionable recommendations to the prescribers. A selection of unambiguous texts was identified as starting point to generate standard texts.

Upregulation of P-Glycoprotein and Breast Cancer Resistance Protein Activity in Newly Developed <i>in Vitro</i> Rat Blood–Brain Barrier Spheroids Using Advanced Glycation End-Products

Upregulation of P-Glycoprotein and Breast Cancer Resistance Protein Activity in Newly Developed <i>in Vitro</i> Rat Blood–Brain Barrier Spheroids Using Advanced Glycation End-Products

Helicobacter pylori Efflux Pumps: A Double-Edged Sword in Antibiotic Resistance and Biofilm Formation

Helicobacter pylori is a major pathogen associated with various gastric diseases. Despite decades of research, the treatment of H. pylori remains challenging. One of the primary mechanisms contributing to failures of therapies targeting this bacterium is genetic mutations in drug target sites, although the growing body of scientific data highlights that efflux pumps may also take part in this process. Efflux pumps are proteinaceous transporters actively expelling antimicrobial agents from the interior of the targeted cells and reducing the intracellular concentration of these compounds. Considering that efflux pumps contribute to both antimicrobial resistance and biofilm formation, an in-depth understanding of their properties may constitute a cornerstone in the development of novel therapeutics against H. pylori. In line with this, the aim of the current review is to describe the multitude of efflux pumps produced by H. pylori and present the data describing the involvement of these proteins in tolerance and/or resistance to various classes of antimicrobial substances.

DLL4-targeted CAR-T therapy sensitizes neoadjuvant chemotherapy via eliminating cancer stem cells and reshaping immune microenvironment in HER2+ breast cancer

BackgroundNeoadjuvant therapy with trastuzumab, pertuzumab and paclitaxel (THP) has significantly improved the prognosis of patients with human epidermal growth factor receptor 2 (HER2)+ breast cancer (BC). However, there remains a...

The Antiviral Effects of Heat-Killed Lactococcus lactis Strain Plasma Against Dengue, Chikungunya, and Zika Viruses in Humans by Upregulating the IFN-α Signaling Pathway

The growing risk of contracting viral infections due to high-density populations and ecological disruptions, such as climate change and increased population mobility, has highlighted the necessity for effective antiviral treatment and preventive measures against Dengue virus (DENV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Recently, there has been increasing attention on the use of probiotics as a potential antiviral option to reduce virus infections. The present study aimed to assess the immunomodulatory effects of heat-killed Lactococcus lactis strain plasma (LC-Plasma) on peripheral blood mononuclear cells (PBMCs) and its subsequent antiviral response against DENV, CHIKV, and ZIKV. To evaluate the immunomodulatory effects of LC-Plasma on PBMCs isolated from healthy individuals, PBMCs were cultured at a density of 2 × 105 cells/well and stimulated with 10 µg/mL of LC-Plasma. LC-plasma-stimulated PBMCs demonstrated elevated interferon-alpha (IFN-α) production and cluster of differentiation 86 (CD86) and human leukocyte antigen-DR isotype (HLA-DR) upregulation, potentially linked to plasmacytoid dendritic cell (pDC) activation. The replication of DENV, CHIKV, and ZIKV was dose-dependently inhibited when Huh-7 cells were stimulated with LC-Plasma-stimulated PBMC supernatant (LCP Sup). IFN-stimulated gene (ISG) expression, including IFN-stimulated gene 15 (ISG15), IFN-stimulated exonuclease gene 20 (ISG20), IFN-induced transmembrane protein 1 (IFITM-1), myxovirus resistance protein A (MxA), and radical S-adenosyl methionine domain-containing protein 2 (RSAD2), was significantly upregulated in LCP Sup-stimulated Huh-7 cells. Findings from this study indicate that LC-Plasma has the potential to induce IFN-α production, leading to an enhancement in the expression of ISGs and contributing to a broad-spectrum antiviral response. Thus, LC-Plasma may serve as a rational adjunctive treatment to ameliorate viral diseases, warranting future clinical trials.

Reversal Potentials of Tween 20 in ABC Transporter-Mediated Multidrug-Resistant Cancer and Treatment-Resistant Depression Through Interacting with Both Drug-Binding and ATP-Binding Areas on MDR proteins

Drug efflux transporters, especially those belonging to the ATP-binding cassette (ABC) transporter superfamily, play a crucial role in various drug resistance issues, including multidrug resistance (MDR) in cancer and treatment-resistant depression (TRD) in individuals with major depressive disorder. Key transporters in this context include P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP). This study aimed to investigate the modulatory effects of polyoxyethylene (20) sorbitan monolaurate (Tween 20) on these efflux transporters in vitro and to evaluate its potential for overcoming drug resistance in two models: an in vitro cancer MDR model and an in vivo TRD model. The findings indicated that 0.001% Tween 20 significantly inhibited the efflux actions of all three transporters. Additionally, 0.005% Tween 20 effectively reversed resistance to paclitaxel, vincristine, doxorubicin, and mitoxantrone in various cancer MDR cell lines. In the in vivo depression-like behavior model, 0.01% Tween 20 markedly enhanced the antidepressant and anxiolytic effects of fluoxetine. Given its strong inhibitory effects on P-gp, MRP1, and BCRP, along with its capacity to reverse drug resistance both in vitro and in vivo, Tween 20 is a compelling candidate for tackling transporter-mediated drug resistance.

Pre-ADMET studies of 5-(3',4'-dihydroxyphenyl)-γ-valerolactone, the bioactive intestinal metabolite of proanthocyanidins.

5-(3',4'-Dihydroxyphenyl)-γ-valerolactone (VL) is a bioactive metabolite resulting from the gut microbial metabolism of proanthocyanidins and flavonoids, known for its health-promoting effects, including antidiabetic and anti-inflammatory activities. Although VL has been observed in different in vivo studies, its pre-absorption, distribution, metabolism, excretion, toxicity (ADMET)properties have rarely been investigated. This study aims to address this gap by evaluating the pre-ADMET properties of VL for the first time. Also, the understanding of these properties is significant for correlating the encountered activities to this metabolite. In vitro absorption studies revealed that VL is rapidly metabolized and absorbed as its sulfate phase II conjugate (valerolactone sulfate), which enters systemic circulation and mildly activates the Breast Cancer Resistance Protein efflux transporter. In human S9 liver fraction, a mixture of liver enzymes used to simulate in vivo liver metabolism, VL is metabolized into glucuronic phase II conjugates (valerolactone glucuronide 1 [VLG1] and 2 [VLG2]) with a half-life of 8.72 min and an 80% conversion rate. In human liver microsomes, VL is metabolized at a slower rate (half-life of 23.08 min), suggesting that oxidative metabolism is secondary. Additionally, VL did not activate the pregnane X receptor or inhibit Cytochrome P3A4 (CYP3A4) and Cytochrome P1A2(CYP1A2) enzymes, indicating no risk of herb-drug interactions with coadministered prescription drugs.

Hypertensive Nephropathy Changes the Expression of Drug-Metabolizing Enzymes and Transporters in Spontaneously Hypertensive Rat Liver and Kidney.

Hypertensive nephropathy (HN) has become one of the main causes of end-stage renal disease. Drug combination therapy is a common clinical treatment for HN. However, the impact of HN on drug-metabolizing enzymes and transporters, which may lead to drug-drug interactions (DDIs) and even trigger toxic side effects, remains unclear. The aim of this study was to investigate changes in major drug-metabolizing enzymes and transporters in the liver and kidney of HN rats to improve the scientific foundations for the clinical treatment of HN. Spontaneously hypertensive rats (SHRs) were used as an animal HN model because their hypertension is similar to that of humans. Wistar-Kyoto rats (WKYs) were used as the control group. Body weight, blood pressure, hematoxylin-eosin (HE) staining and biochemical analysis were performed to evaluate whether the HN model was successfully constructed. Quantitative real-time polymerase chain reaction (PCR) and western blotting were used to evaluate the mRNA and protein expression of drug-metabolizing enzymes, transporters and related nuclear transcription factors. In HN rats, the mRNA expression of the drug-metabolizing enzymes cytochrome P450 (Cyp) 2b1, Cyp2c11, Cyp3a1 and Cyp7a1 was significantly upregulated. The protein level of CYP3A1 was consistent with its mRNA expression. Interestingly, the mRNA expression of the hepatic transporters organic cation transporter (Oct) 1, Oct2, organic anion transporter (Oat) 1, Oat2, multidrug resistant protein (Mrp) 2, multidrug resistance (Mdr) 1, organic anion transporting polypeptide (Oatp) 1b2 and na+/taurocholate cotransporting polypeptide (Ntcp) was also markedly upregulated. This may be directly influenced by the upregulation of the expression of the nuclear receptors farnesoid X receptor (Fxr), pregnane X receptor (Pxr), liver X-activated receptor (Lxr) and constitutive androstane receptor (Car). In the kidney of HN rats, the mRNA level of the drug-metabolizing enzyme Cyp2b1 significantly increased, while levels of Cyp1a1, Cyp2c11, Cyp3a1 and Cyp3a2 did not significantly change. The mRNA expression of the transporters multidrug and toxin extrusion (Mate) 1 and Mrp2 was obviously increased but was markedly depressed for peptide transporters (Pept) 1 and Pept2. These changes may be related to the cross effects of Pxr, Fxr and Car in kidney. HN pathological status can alter the expression of drug-metabolizing enzymes and transporters in the liver and kidney to varying degrees, thus affecting the disposition of substrate drugs in vivo. This suggests that to avoid potential risks, caution should be exercised when administering combination therapy for HN treatment.

Are Δ9-Tetrahydrocannabinol and Its Major Metabolites Substrates or Inhibitors of Placental or Human Hepatic Drug Solute-Carrier Transporters?

Δ9-Tetrahydrocannabinol (THC) is the primary psychoactive component of cannabis which is being increasingly consumed by pregnant people. In humans, THC is sequentially metabolized in the liver to its circulating metabolites 11-hydroxy-THC (11-OH-THC, psychoactive) and 11-nor-9-carboxy-THC (THC-COOH, non-psychoactive). Human and macaque data show that fetal exposure to THC is considerably lower than the corresponding maternal exposure. Through perfused human placenta studies, we showed that this is due to the active efflux of THC (fetal-to-maternal) by a placental transporter(s) other than P-glycoprotein or breast cancer resistance protein. The identity of this placental transporter(s) as well as whether THC or its metabolites are substrates or inhibitors of hepatic solute carrier transporters is unknown. Therefore, we investigated whether 5 μM THC, 0.3 μM 11-OH-THC, and 2.5 μM THC-COOH are substrates and/or inhibitors of placental or hepatic solute carrier transporters at their pharmacologically relevant concentrations. Using HEK cells overexpressing human OATP1B1, OATP1B3, OATP2B1, OCT1, OCT3, OAT2, OAT4, or NTCP, and prototypic substrates/inhibitors of these transporters, we found that THC and THC-COOH were substrates but not inhibitors of OCT1. THC-COOH was a weak substrate of OCT3 and a weak inhibitor of OAT4. THC, 11-OH-THC, and THC-COOH were found not to be substrates/inhibitors of the remaining transporters investigated.

A disease resistance protein triggers oligomerization of its NLR helper into a hexameric resistosome to mediate innate immunity.

NRCs are essential helper NLR (nucleotide-binding domain and leucine-rich repeat) proteins that execute immune responses triggered by sensor NLRs. The resting state of NbNRC2 was recently shown to be a homodimer, but the sensor-activated state remains unclear. Using cryo-EM, we determined the structure of sensor-activated NbNRC2, which forms a hexameric inflammasome-like resistosome. Mutagenesis of the oligomerization interface abolished immune signaling, confirming the functional significance of the NbNRC2 resistosome. Comparative structural analyses between the resting state homodimer and sensor-activated homohexamer revealed substantial rearrangements, providing insights into NLR activation mechanisms. Furthermore, structural comparisons between NbNRC2 hexamer and previously reported CC-NLR pentameric assemblies revealed features allowing an additional protomer integration. Using the NbNRC2 hexamer structure, we assessed the recently released AlphaFold 3 for predicting activated CC-NLR oligomers, revealing high-confidence modeling of NbNRC2 and other CC-NLR amino-terminal α1 helices, a region proven difficult to resolve structurally. Overall, our work sheds light on NLR activation mechanisms and expands understanding of NLR structural diversity.

Effects of GLPG3970 on Sulfasalazine and Methotrexate Pharmacokinetics in Healthy Adults: Two Open-Label, Phase I, Drug-Drug Interaction Studies.

GLPG3970 is a selective salt-inducible kinase 2/3 inhibitor intended for the treatment of inflammatory diseases. In vitro studies suggest GLPG3970 strongly inhibits breast cancer resistance protein (BCRP), indicating a possible interaction with BCRP substrates such as sulfasalazine (SSZ; a probe substrate for intestinal BCRP inhibition) and methotrexate (MTX), both inflammatory disease medications. Two open-label, nonrandomized, phase I, drug-drug interaction (DDI) studies assessed the pharmacokinetics of SSZ 1,000 mg (NCT04720183) and MTX 7.5 mg (EudraCT: 2020-000391-37) with and without GLPG3970 350 mg. Healthy participants aged 18-55 years with wild-type homozygous BCRP genotype (c421C/C) received: SSZ on day (D)1, GLPG3970 + SSZ on D5, and GLPG3970 2 hours after SSZ on D9 (N = 8; SSZ/GLPG3970 DDI study); MTX on D1, GLPG3970 + MTX on D5, and GLPG3970 on D6-8 (N = 15; MTX/GLPG3970 DDI study). Primary end points were AUC and Cmax ("exposure") of SSZ and its metabolite (sulfapyridine [SPD]), SPD:SSZ AUC ratio (SSZ/GLPG3970 study), and AUC and Cmax ("exposure") of MTX (MTX/GLPG3970 study). DDIs were evaluated using the geometric mean ratio of each end point; a > 2-fold increase in SSZ or MTX exposure was deemed clinically relevant. GLPG3970 demonstrated mild inhibition of intestinal BCRP in vivo: GLPG3970 + SSZ increased SSZ exposure ~1.7-1.8-fold and decreased SPD:SSZ ratio ~ 2-fold vs. SSZ alone. GLPG3970 administered 2 hours after SSZ did not change the magnitude of the interaction. GLPG3970 + MTX had no relevant effect on MTX pharmacokinetics vs. MTX alone. Therefore, the strong in vitro BCRP inhibition was not confirmed in vivo. No safety concerns were observed when GLPG3970 was coadministered with SSZ or MTX.

Use of the Puccinia sorghi haustorial transcriptome to identify and characterize AvrRp1-D recognized by the maize Rp1-D resistance protein.

The common rust disease of maize is caused by the obligate biotrophic fungus Puccinia sorghi. The maize Rp1-D allele imparts resistance against the P. sorghi IN2 isolate by initiating a defense response that includes a rapid localized programmed cell death process, the hypersensitive response (HR). In this study, to identify AvrRp1-D from P. sorghi IN2, we employed the isolation of haustoria, facilitated by a biotin-streptavidin interaction, as a powerful approach. This method proves particularly advantageous in cases where the genome information for the fungal pathogen is unavailable, enhancing our ability to explore and understand the molecular interactions between maize and P. sorghi. The haustorial transcriptome generated through this technique, in combination with bioinformatic analyses such as SignalP and TMHMM, enabled the identification of 251 candidate effectors. We ultimately identified two closely related genes, AvrRp1-D.1 and AvrRp1-D.2, which triggered an Rp1-D-dependent defense response in Nicotiana benthamiana. AvrRp1-D-induced Rp1-D-dependent HR was further confirmed in maize protoplasts. We demonstrated that AvrRp1-D.1 interacts directly and specifically with the leucine-rich repeat (LRR) domain of Rp1-D through yeast two-hybrid assay. We also provide evidence that, in the absence of Rp1-D, AvrRp1-D.1 plays a role in suppressing the plant immune response. Our research provides valuable insights into the molecular interactions driving resistance against common rust in maize.

DLK1 Is Associated with Stemness Phenotype in Medullary Thyroid Carcinoma Cell Lines

Medullary thyroid carcinoma (MTC) is a rare and aggressive tumor, often requiring systemic treatment in advanced or metastatic stages, where drug resistance presents a significant challenge. Given the role of cancer stem cells (CSCs) in cancer recurrence and drug resistance, we aimed to identify CSC subpopulations within two MTC cell lines harboring pathogenic variants in the two most common MEN2-associated codons. We analyzed 15 stemness-associated markers, along with well-established thyroid stem cell markers (CD133, CD44, and ALDH1), a novel candidate (DLK1), and multidrug resistance proteins (MRP1 and MRP3). The ability to efflux the fluorescent dye Hoechst 3342 and form spheroids, representing CSC behavior, was also assessed. MZ-CRC-1 cells (p.M918T) displayed higher expressions of canonical markers, DLK1, and MRP proteins than TT cells (p.C634W). MZ-CRC-1 cells also formed more spheroids and showed less dye accumulation (p < 0.0001). Finally, we observed that DLK1+ cells (those expressing DLK1) in both cell lines exhibited significantly higher levels of stemness markers compared to DLK1− cells (those lacking DLK1 expression). These findings underscore DLK1’s role in enhancing the stemness phenotype, providing valuable insights into MTC progression and resistance and suggesting potential therapeutic implications.

HPRT1: a preliminary investigation on its involvement in nasopharyngeal carcinoma

BackgroundAccumulating evidences have stressed the association between hypoxanthine phosphoribosyl transferase 1 (HPRT1) overexpression and the poor prognosis of various cancers. Our study, herein, preliminarily investigates the involvement of HPRT1 in nasopharyngeal carcinoma (NPC).MethodsData from TCGA were applied to read HPRT1 expression in diverse cancers including NPC and to predict the prognosis of NPC patients. The total RNA and protein from NPC cells and nasopharyngeal epithelial cells NP460 were extracted to quantify HPRT1 expression. Following the completion of transfection, the proliferation and migration of NPC cells were determined employing MTT, colony formation and western blot assay (the quantification on expressions of protein related to proliferation and migration).ResultsHPRT1 was differentially expressed in diverse cancers yet particularly highly expressed in NPC, and high HPRT1 expression was related to the poor prognosis of NPC patients. Also, HPRT1 expression was higher in NPC cells and its silencing diminished the viability and proliferation of NPC cells and reduced the expressions of CyclinD1, CyclinE, Multidrug Resistance Protein 1 (MDR1), matrix metalloproteinase (MMP)-2, and MMP-9.ConclusionThis study preliminarily explored the involvement of HPRT1 in NPC based on some cellular assays in vitro, which may provide evidence for investigating the specific mechanism underlying the effects of HPRT1 in cancers.

Hyaluronic acid-functionalized ruthenium photothermal nanoenzyme for enhancing osteosarcoma chemotherapy: Cascade targeting and bidirectional modulation of drug resistance

Insufficient drug delivery efficiency in vivo and robust drug resistance are two major factors to induce suboptimal efficacy in chemotherapy of osteosarcoma (OS). To address these challenges, we developed polysaccharide hyaluronic acid (HA)-functionalized ruthenium nanoaggregates (Ru NAs) to enhance the chemotherapy of doxorubicin (DOX) for OS. These NAs, comprising Ru nanoparticles (NPs) and alendronate-modified HA (HA-ALN), effectively load DOX, resulting in DOX@Ru-HA-ALN NAs. The combination of HA and ALN in NAs ensures outstanding cascade targeting towards tumor-invaded bone tissues and CD44-overexpressing tumor cells, maximizing therapeutic efficacy while minimizing off-target effects. Concurrently, the Ru NPs in NAs function as “smart” photoenzymatic agent to not only in situ relieve hypoxia of OS via the catalysis of overexpressed H2O2 to produce O2, but also generate mild photothermal effect under 808-nm laser irradiation. They can bidirectionally overcome drug resistance of DOX via downregulation of resistance-related factors including multi-drug resistant associate protein, P-glycoprotein, heat shock factor 1, etc. The integration of cascade targeting with bidirectional modulation of drug resistance positions Ru-HA-ALN NAs to substantially enhance DOX chemotherapy for OS. Therefore, the present work highlights the potential of polysaccharide-functionalized nanomaterials in advancing tumor chemotherapy by addressing challenges of both delivery efficiency and drug resistance.

Ticagrelor modestly raises plasma riboflavin concentration in humans and inhibits riboflavin transport by BCRP and MRP4.

Riboflavin (vitamin B2) has been proposed as a biomarker for breast cancer resistance protein (BCRP) activity. In recent studies in mice, cynomolgus monkeys, and humans, BCRP-inhibiting drugs increased the plasma concentration of riboflavin. We showed recently that ticagrelor inhibits BCRP and raises the plasma concentrations of the BCRP substrate rosuvastatin in healthy volunteers. In the same drug-drug interaction study, we now investigated whether ticagrelor affects the plasma concentrations of riboflavin. Intake of 90 mg ticagrelor increased the ratio between the peak plasma riboflavin concentration and the fasting riboflavin concentration before ticagrelor administration by 1.20-fold (90% confidence interval, 1.10-1.32; P = 0.006) compared to placebo. In vitro, riboflavin was transported by BCRP and multidrug-resistance-associated protein 4 (MRP4) but no clear transport was observed by MRP2, MRP3, or the P-glycoprotein. Moreover, ticagrelor inhibited the transport of riboflavin in BCRP- and MRP4-expressing membrane vesicles with unbound 50% inhibitory concentrations of 0.020 and 1.1μM, respectively. Based on vesicle and tissue protein expression data, the small intestinal MRP4-mediated efflux clearance of riboflavin (1.2-1.4 nL/min/mg) was estimated to be similar to that mediated by BCRP (0.23-1.3 nL/min/mg). As MRP4 is expressed in the basolateral membrane of enterocytes, it may facilitate the absorption of riboflavin and impair the utility of riboflavin as a biomarker of intestinal BCRP. To conclude, ticagrelor modestly raises the plasma concentration of riboflavin probably by inhibiting intestinal BCRP. Inhibition of intestinal MRP4 may have reduced the absorption of riboflavin and limited the effect of ticagrelor on riboflavin levels.

Synergistic anticancer efficacy of polydatin and sorafenib against the MCF-7 breast cancer cell line via inhibiting of PI3K/AKT/mTOR pathway and reducing resistance to treatment

Polydatin (PD), a glucoside derivative of resveratrol, has been investigated for its potential to mitigate sorafenib (SOF) side effects and combat multidrug resistance in cancer treatment. The study evaluated its mechanism of action for inhibiting the protein kinase B/mTOR pathway in promoting breast cancer proliferation. The combined PD and SOF have synergistic effects with a combination index (CI) < 1 in the liver (HepG2) and breast (MCF-7) cancer cell lines. Molecular docking studies were conducted to analyze interactions of PD& SOF with protein kinases as well as apoptotic and multidrug resistance proteins, including AKT1, PI3K, mTOR, Apaf-1, and ABCB1 in MCF-7 cells. Experimental validation through real-time PCR confirmed. PD has a strong binding affinity, particularly with AKT1 (-56 kcal/mol) and ABCB1 (-27.16 kcal/mol), a gene associated with multidrug resistance. These interactions were linked to anti-proliferative anti-angiogenic effects and reduced resistance to treatment, demonstrating PD has potential therapeutic benefits. Furthermore, PD combined with SOF induced apoptosis, inhibited cell growth, and arrested MCF-7 cells in the sub-G1 phase with increased intracellular ROS. This was accompanied by reduced expression of AKT1 and ABCB1 genes, reinforcing the anticancer efficacy of PD/SOF combination therapy. In conclusion, the findings suggest that PD/SOF could serve as a promising anticancer treatment strategy, warranting further investigation for potential clinical applications and mechanistic studies in vivo.

Mitogenome of a new Ramazzottius species (Tardigrada: Eutardigrada: Ramazzottiidae) discovered in rock pools along with its temperature and desiccation-related proteins repertoire

AbstractRamazzottius is a widespread genus of tardigrades with extreme cryptobiotic capabilities. Thanks to its ability to survive desiccation and freezing, this genus is usually recorded from harsh habitats such as exposed mosses and lichens and rock pools. In the last years, research focused on both describing Ramazzottius diversity and revealing the molecular mechanisms behind their cryptobiotic capabilities. Despite the research efforts in these fields, much still remains to be discovered. Here we describe a new Ramazzottius species from an Italian rock pool by means of integrative taxonomy (morphology, morphometry, and DNA sequencing) and sequenced its genome with Nanopore technology to provide an assembled mitogenome and annotate its Temperature and Desiccation Resistance Proteins (TDPR) repertoire. The new gonochoric species is phylogenetically close to the parthenogenetic R. varieornatus, a strain of which (YOKOZUNA-1) has been adopted as model organism for the study of cryptobiosis. The mitogenome of the new species shows perfect synteny with R. varieornatus and shares with it most of the TDPR genes. The relative genetic similarity of the new species to the model R. varieornatus, combined with unique biological traits (for example the difference in reproductive mode and the unique habitat it colonizes), makes the new species a potential new addition to the range of model tardigrade species.

Pomolic Acid: Cancer Molecular Targets, Plant Extraction Yields and Availability

Pomolic acid (3-beta,19alpha-Dihydroxy-urs-12-en-28-oic acid, PA) is a naturally occurring pentacyclic triterpenoid. Derived from the mevalonate pathway through cyclization of 2,3-oxidosqualene, it has been widely found in several plant species. In the mid-1960s, PA was identified as the genuine aglycone of triterpenoid saponins from Sanguisorba officinalis, and studies on its biological activities began in 1989. Since then, several pharmacological properties have been described for this compound, including antitumoral activity. PA induced cell death in tumors, such as lung, brain, breast, and sensitive and resistant leukemia. Additionally, PA modulates resistant proteins and events involved in metastasis. Even though PA constitutes an important candidate for new treatment against several cancers, its availability hampers the evolution of PA studies toward clinical evaluation. This review discusses the limitations of PA availability, the recent approaches to improve it, and other aspects of the antitumoral studies on PA activity.