Alveolar Cell Line Research Articles

Inhibition of Chemoresistance in Primary Tumor Cells by Camellia sinensis non fermentatum Extract Noviphenone (NPE®).

Despite improvements in cancer therapy, life expectancy after tumor recurrence remains low. Relapsed cancer is characterized by drug resistance, often mediated through overexpression of multidrug resistance (MDR) genes. Camellia sinensis non fermentatum extract is known for its anticancer properties in several cancer cell lines and might improve cancer therapy outcome after tumor recurrence. Embryonal rhabdomyosarcoma cell lines, alveolar rhabdomyosarcoma cell lines and primary rhabdomyosarcoma MAST139 cells were used to test NPE® effects on cell viability in combination with chemotherapeutic agents. Cell viability was measured by the WST-1 assay and CV staining. Gene expression levels of chemotherapy-induced efflux pumps and their activity was assessed upon NPE® treatment by measuring doxorubicin retention through evaluation of the autofluorescence signal. Administration of increasing doxorubicin concentrations triggered immediate adaptation to the drug, which was surprisingly overcome by the addition of NPE®. Investigating the mechanism of immediate adaptation, MDR1 gene overexpression was observed upon doxorubicin treatment. Although NPE® did not alter pump gene expression, it was able to reduce pump activity, thus allowing the chemotherapeutic agent to stay inside the cells to exert its full anticancer activity. NPE® might improve chemotherapeutic treatment by re-sensitizing relapsed tumors to anticancer drugs. Fighting MDR represents the key to overcome tumor relapse and improve the overall survival of cancer patients.

Abstract 3909: Potential antitumor effect of a pan-PI3K inhibitor ZSTK474 on human sarcoma cell lines

Abstract Phosphatidylinositol-3 kinase (PI3K) is a key signaling molecule for tumor growth and survival, thus the PI3K pathway has been thought to be a promising target for cancer therapy. We previously identified a novel phosphatidylinositol-3 kinase (PI3K) inhibitor, ZSTK474, by its similarity of antiproliferative profile across the JFCR39 cancer cell line panel to a known PI3K inhibitor, LY294002. Since then, ZSTK474 has been evaluated in preclinical models as well as in clinical trials in the US and Japan against a range of advanced solid tumors. The US trial revealed that three of four sarcoma patients exhibited stable disease, suggesting possible clinical benefit in this disease. Treatment of patients with advanced sarcoma remains challenging due to lack of effective medicine. Therefore the results of clinical trial prompted us to examine antitumor activity of this compound in various subtypes of sarcomas. To this end, we developed a sarcoma panel comprising of 17 human sarcoma cell lines from a variety of subtypes and investigated the effect of ZSTK474 across the panel and compare it with those of other molecularly targeted agents and clinically used chemotherapeutic agents for the treatment of sarcoma, such as doxorubicin, paclitaxel and gemcitabine. As a result, ZSTK474 exhibited a unique antiproliferative profile that was similar to other PI3K inhibitor but clearly different from conventional chemotherapeutic drugs examined, as we previously reported using JFCR39 carcinoma cell line panel. Indeed, ZSTK474 inhibited PI3K-downstream pathways, in parallel to growth inhibition, in all the sarcoma cell lines examined, showing proof-of-concept of PI3K inhibition. Of note, ZSTK474 exerted a potent antiproliferative effect on SW684, a fibrosarcoma cell line and MES-SA/Dx5, and a uterine sarcoma cell line that acquired resistance to doxorubicin via overexpression of P-glycoprotein, while both exhibited resistance to most of the chemotherapeutic agents examined. Moreover, ZSTK474 induced extensive apoptosis selectively in Ewing’s sarcoma and alveolar rhabdomyosarcoma cell lines, both of which harbor chromosomal translocations and resulting fusion genes, EWSR1-FLI1 and PAX3-FOXO1, respectively, whereas remaining sarcoma cell lines as well as carcinoma cell lines examined so far hardly underwent apoptosis. Additional cell lines from synovial sarcoma harboring SS18-SSX1/2 fusion gene also underwent apoptosis, suggesting preferential induction of apoptosis in oncogenic chromosomal translocation positive sarcoma cells. Finally, animal experiments using nude mice bearing human sarcoma xenograft confirmed the antitumor activity of ZSTK474 in vivo, with superior efficacy observed in translocation-positive cells. These results suggest that ZSTK474 could be a promising drug candidate for sarcomas, especially those harboring oncogenic chromosomal translocation. Citation Format: Shingo Dan, Naomi Tamaki, Nachi Namatame, Yuya Yoshizawa, Mutsumi Okamura, Yumiko Nishimura, Kanami Yamazaki, Shin-ichi Yaguchi. Potential antitumor effect of a pan-PI3K inhibitor ZSTK474 on human sarcoma cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3909.

Manganese Uptake by A549 Cells is Mediated by Both ZIP8 and ZIP14.

The alveolar epithelia of the lungs require manganese (Mn) as an essential nutrient, but also provide an entry route for airborne Mn that can cause neurotoxicity. Transporters involved in Mn uptake by alveolar epithelial cells are unknown. Recently, two members of the Zrt- and Irt-like protein (ZIP) family of metal transporters, ZIP8 and ZIP14, have been identified as crucial Mn importers in vivo. ZIP8 is by far most abundantly expressed in the lungs, whereas ZIP14 expression in the lungs is low compared to other tissues. We hypothesized that Mn uptake by alveolar epithelial cells is primarily mediated by ZIP8. To test our hypothesis, we used A549 cells, a type II alveolar cell line. Mirroring the in vivo situation, A549 cells expressed higher levels of ZIP8 than cell models for the liver, intestines, and kidney. Quantification of ZIP8 and ZIP14 revealed a strong enrichment of ZIP8 over ZIP14 in A549 cells. Using siRNA technology, we identified ZIP8 and ZIP14 as the major transporters mediating Mn uptake by A549 cells. To our surprise, knockdown of either ZIP8 or ZIP14 impaired Mn accumulation to a similar extent, which we traced back to similar amounts of ZIP8 and ZIP14 at the plasma membrane. Our study highlights the importance of both ZIP8 and ZIP14 in Mn metabolism of alveolar epithelial cells.

Biocompatible dialdehyde cellulose/poly(vinyl alcohol) hydrogels with tunable properties

Solubilized dialdehyde cellulose (DAC), an efficient crosslinking agent for poly(vinyl alcohol) (PVA), provides less toxic alternative to current synthetic crosslinking agents such as glutaraldehyde, while simultaneously allowing for the preparation of hydrogels with comparably better characteristics. PVA/DAC hydrogels prepared using 0.5, 1 and 1.5 wt% of DAC were analyzed in terms of mechanical, swelling and cytotoxicity characteristics. Materials properties of PVA/DAC hydrogels range from stiff substances to soft viscoelastic gels capable of holding large amounts of water. Superior mechanical properties, porosity and surface area in comparison with analogical PVA/glutaraldehyde hydrogels were observed. Biological studies showed low toxicity and good biocompatibility of PVA/DAC hydrogels. Potential of PVA/DAC in mesh-controlled release of biologically active compounds was investigated using ibuprofen, rutin and phenanthriplatin. Hydrogel loaded with anticancer drug phenantriplatin was found effective against alveolar cancer cell line A549 under in vitro conditions.

Pectin/Chitosan/Tripolyphosphate Nanoparticles: Efficient Carriers for Reducing Soil Sorption, Cytotoxicity, and Mutagenicity of Paraquat and Enhancing Its Herbicide Activity

As a potent herbicide capable of contaminating water and soil environments, paraquat, which is still widely used worldwide, is toxic to mammals, algae, aquatic animals, etc. Paraquat was loaded on novel nanoparticles composed of pectin, chitosan, and sodium tripolyphosphate (PEC/CS/TPP). The size, polydispersity index, and ζ potential of nanoparticles were characterized. Further assessments were carried out by SEM, AFM, FT-IR, and DSC. The encapsulation was highly efficient, and there was a delayed release pattern of paraquat. The encapsulated herbicide was less toxic to alveolar and mouth cell lines. Moreover, the mutagenicity of the formulation was significantly lower than those of pure or commercial forms of paraquat in a Salmonella typhimurium strain model. The soil sorption of paraquat and the deep soil penetration of the nanoparticle-associated herbicide were also decreased. The herbicidal activity of paraquat for maize or mustard was not only preserved but also enhanced after encapsulation. It was concluded that paraquat encapsulation with PEC/CS/TPP nanoparticles is highly efficient and the formulation has significant herbicide activity. It is less toxic to human environment and cells, as was evidenced by less soil sorption, cytotoxicity, and mutagenicity. Hence, paraquat-loaded PEC/CS/TPP nanoparticles have potential advantages for future use in agriculture.

Liposome mediated-CYP1A1 gene silencing nanomedicine prepared using lipid film-coated proliposomes as a potential treatment strategy of lung cancer

The occurrence of lung cancer is linked with tobacco smoking, mainly through the generation of polycyclic aromatic hydrocarbons (PAHs). Elevated activity of cytochrome P4501A1 (CYP1A1) plays an important role in the metabolic processing of PAHs and its carcinogenicity. The present work aimed to investigate the role of CYP1A1 gene in PAH-mediated growth and tumor development in vitro and using an in vivo animal model. RNAi strategy was utilized to inhibit the overexpression of CYP1A1 gene using cationic liposomes generated using a lipid film-coated proliposome microparticles. Treatment of PAH-induced human alveolar adenocarcinoma cell line with cationic liposomes carrying CYP1A1 siRNA resulted in down regulation of CYP1A1 mRNA, protein as well as its enzymatic activity, triggering apoptosis and inhibiting multicellular tumor spheroids formation in vitro. Furthermore, silencing of CYP1A1 gene in BALB/c nude xenografts inhibited tumor growth via down regulation of CYP1A1 expression. Altogether, our findings showed that liposome-based gene delivery technology is a viable and stable approach for targeting cancer causing genes such as CY1PA1. This technology facilitated by the use of sugar particles coated with lipid films has demonstrated ability to generate anticancer effects that might be used in the future for therapeutic intervention and treatment of lung cancer.

The 3′UTR of the α6 integrin message regulates localization of α6β4 integrin heterodimers

The α6β4 integrin heterodimer is an essential component of hemidesmosomes (HDs) and HD-related structures, which adhere epithelial cells to the underlying extracellular matrix. In this study, we focused on the importance of the α6 integrin 3′ untranslated region (UTR) in α6β4 integrin localization. To do so, A549 cells (a type II lung alveolar cell line) and immortalized human epidermal keratinocytes (iHEK) were infected with adenovirus encoding the entire α6 integrin protein with or without portions of its 3′UTR. In infected A549 cells, we detected α6β4 integrin heterodimers containing the product of the adenovirus, regardless of whether the α6 integrin 3′UTR was present. However, only those α6 integrin proteins whose messages contained bases 4770–5633 of the α6 integrin 3′UTR were targeted to matrix adhesion sites. Moreover, overexpression of the full length α6 integrin 3′UTR, minus the coding sequence, in A549 cells disrupts the localization of endogenous α6β4 integrin heterodimers. Following infection of iHEKs with the same adenovirus, the induced α6 integrin protein localizes to HDs regardless of whether its message possessed a 3′UTR. In sharp contrast, in α6 integrin depleted iHEKs, restoring α6 integrin expression using the coding sequence alone via adenoviral transduction resulted in α6 integrin preferentially forming α6β1 rather than α6β4 integrin heterodimers. α6β4 integrin was only observed in knocked down cells following infection of adenovirus encoding the α6 integrin coding sequence with its 3′UTR. In summary, our data indicate that the α6 integrin 3′UTR is a key regulator of α6β4 integrin heterodimer assembly and incorporation at sites of cell-matrix adhesion.

Microparticles of Lamivudine-Poly-ε-Caprolactone Conjugate for Drug Delivery via Internalization by Macrophages.

The past decade may be considered as revolutionary in the research field focused on the physiological function of macrophages. Unknown subtypes of these cells involved in pathological mechanisms were described recently, and they are considered as potential drug delivery targets. The innate ability to internalize foreign bodies exhibited by macrophages can be employed as a therapeutic strategy. The efficiency of this uptake depends on the size, shape and surface physiochemical properties of the phagocyted objects. Here, we propose a method of preparation and preliminary evaluation of drug-polymer conjugate-based microspheres for macrophage targeted drug delivery. The aim of the study was to identify crucial uptake-enhancing parameters for solid, surface modified particles. A model drug molecule—lamivudine—was conjugated with poly-ε-caprolactone via ring opening polymerization. The conjugate was utilized in a solvent evaporation method technique to form solid particles. Interactions between particles and a model rat alveolar cell line were evaluated by flow cytometry. The polymerization product was characterized by a molecular weight of 3.8 kDa. The surface of the obtained solid drug-loaded cores of a hydrodynamic diameter equal to 2.4 µm was modified with biocompatible polyelectrolytes via a layer-by-layer assembly method. Differences in the internalization efficiency of four particle batches by the model RAW 264.7 cell line suggest that particle diameter and surface hydrophobicity are the most influential parameters in terms of phagocytic uptake.

Anticancer activity of green synthesised AgNPs from Cymbopogon citratus (LG) against lung carcinoma cell line A549.

The present study is designed to analyse the antibacterial and anticancer effects of silver nanoparticles (AgNPs) synthesised from the Cymbopogon citratus, (lemongrass) (LG-AgNPs), which is widely used in ayurvedic drugs for treating various diseases. The LG-AgNPs were synthesised and characterised using ultraviolet (UV) spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. The characterised LG-AgNPs was subjected to antimicrobial analysis by disc diffusion method against pathogenic bacteria and fungi. Furthermore, the cytotoxicity and anticancer activity of the LG-AgNPs were assessed with lung alveolar carcinoma cell line A549. Results depict that UV-visible spectra of LG-AgNPs showed strong absorption peak at 435 nm. The XRD study exposed LG-AgNPs crystals, which confirmed with TEM analysis exhibiting particle size ranging between 17 and 25.8 nm. The FTIR spectra recorded peaks at 3347, 2126, 1639, 659, 598 and 553 cm-1. The zone of inhibition study proves the LG-AgNPs possessed both antibacterial and antifungal activities. 3-(4, 5-dimethyl thiazoyl-2-yl)-(2,5-diphenyltetrazolium bromide) results show the cytotoxicity effect of LG-AgNPs in lung cancer cells. It also inhibited the cell migration and invasion at the dose of 25 µg ml-1 by increasing the apoptotic gene expression. The results reveal LG-AgNPs possess anticancer activities, proposing that it may be an alternative drug for allopathic drugs with lots of side effects used in lung cancer treatment.

The mTOR Family of Proteins and the Regulation of Trophoblast Invasion by Gas6

Objective: Preeclampsia is an obstetric complication wherein trophoblast invasion is decreased and high levels of serum Gas6 protein are present. Our objective was to assess members of the mTOR family that are plausibly involved in the invasion of trophoblast cells resulting from Gas6/AXL activation. Methods: Human first trimester cell line; (SW71), placental choriocarcinoma cell line (Jeg-3) and pulmonary alveolar type II-like cell line (A549) were treated with Gas6 or Gas6 and R428 (AXL receptor inhibitor) for 24 hours and real time cellular invasion was determined. Western blots were utilized to assess AXL receptor expression in treated and control cells. An Akt/mTOR phospho protein multiplex approach was used to determine the activity of mTOR related proteins. Results: As compared to controls, cell treatments showed: 1) decreased SW71 invasion and increased Jeg-3 and A549 invasion with Gas6, 2) reversal of invasive properties when Gas6 and R428 were co-administered in A549 and SW71 cells, 3) increased expression of pAXL cells with Gas6, 4) decreased pAXL expression when Gas6 and R428 were added, 5) a trend of decreased phosphorylation of mTOR related proteins by Gas6 in trophoblasts, and 6) a trend of increased phosphorylation of mTOR related proteins by Gas6 in lung cancer cells. Conclusions: These experiments revealed that mTOR family members are involved in the activation of AXL receptors during the regulation of cell invasion. The results provide important insight into the mechanism of AXL regulation of trophoblast cell invasion and identify potential avenues that may help in the understanding of obstetric complications associated with the aberrant invasion of trophoblast cells.

Canonical WNT/β-Catenin Signaling Plays a Subordinate Role in Rhabdomyosarcomas.

The development of skeletal muscle from immature precursors is partially driven by canonical WNT/β-catenin signaling. Rhabdomyosarcomas (RMS) are immature skeletal muscle-like, highly lethal cancers with a variably pronounced blockade of muscle differentiation. To investigate whether canonical β-catenin signaling in RMS is involved in differentiation and aggressiveness of RMS, we analyzed the effects of WNT3A and of a siRNA-mediated or pharmacologically induced β-catenin knock-down on proliferation, apoptosis and differentiation of embryonal and alveolar RMS cell lines. While the canonical WNT pathway was maintained in all cell lines as shown by WNT3A induced AXIN expression, more distal steps including transcriptional activation of its key target genes were consistently impaired. In addition, activation or inhibition of canonical WNT/β-catenin only moderately affected proliferation, apoptosis or myodifferentiation of the RMS tumor cells and a conditional knockout of β-catenin in RMS of Ptchdel/+ mice did not alter RMS incidence or multiplicity. Together our data indicates a subordinary role of the canonical WNT/β-catenin signaling for RMS proliferation, apoptosis or differentiation and thus aggressiveness of this malignant childhood tumor.

PARP inhibitors affect growth, survival and radiation susceptibility of human alveolar and embryonal rhabdomyosarcoma cell lines

PurposePARP inhibitors (PARPi) are used in a wide range of human solid tumours but a limited evidence is reported in rhabdomyosarcoma (RMS), the most frequent childhood soft-tissue sarcoma. The cellular and molecular effects of Olaparib, a specific PARP1/2 inhibitor, and AZD2461, a newly synthesized PARP1/2/3 inhibitor, were assessed in alveolar and embryonal RMS cells both as single-agent and in combination with ionizing radiation (IR).MethodsCell viability was monitored by trypan blue exclusion dye assays. Cell cycle progression and apoptosis were measured by flow cytometry, and alterations of specific molecular markers were investigated by, Real Time PCR, Western blotting and immunofluorescence experiments. Irradiations were carried out at a dose rate of 2 Gy (190 UM/min) or 4 Gy (380 UM/min). Radiosensitivity was assessed by using clonogenic assays.ResultsOlaparib and AZD2461 dose-dependently reduced growth of both RH30 and RD cells by arresting growth at G2/M phase and by modulating the expression, activation and subcellular localization of specific cell cycle regulators. Downregulation of phospho-AKT levels and accumulation of γH2AX, a specific marker of DNA damage, were significantly and persistently induced by Olaparib and AZD2461 exposure, this leading to apoptosis-related cell death. Both PARPi significantly enhanced the effects of IR by accumulating DNA damage, increasing G2 arrest and drastically reducing the clonogenic capacity of RMS-cotreated cells.ConclusionsThis study suggests that the combined exposure to PARPi and IR might display a role in the treatment of RMS tumours compared with single-agent exposure, since stronger cytotoxic effects are induced, and compensatory survival mechanisms are prevented.

The crux of positive controls - Pro-inflammatory responses in lung cell models

Positive controls are an important feature in experimental studies as they show the responsiveness of the model under investigation. An often applied reagent for a pro-inflammatory stimulus is the endotoxin lipopolysaccharide (LPS), which has been shown to induce a cytokine release by various cell cultures.The effect of LPS in monocultures of 16HBE14o-, a bronchial cell line, and of A549, an alveolar cell line, were compared in submerged and air-liquid interface cultures, as well as in co-cultures of the two epithelial cells with monocyte-derived macrophages and dendritic cells. The protein and mRNA levels of the two most relevant pro-inflammatory mediators, Tumor necrosis factor alpha (TNF) and Interleukin 8 (CXCL8), were measured after 4 h and 24 h exposure.16HBE14o- cells alone as well as in co-cultures are non-responsive to an LPS stimulus, but an already increased basal expression of both pro-inflammatory mediators after prolonged time in culture was observed. In contrary, A549 in monocultures showed increased CXCL8 production at the gene and protein level after LPS exposure, while TNF-levels were below detection limit. In A549 co-cultured with immune cells both mediators were upregulated.This study shows the importance of a careful evaluation of the culture system used, including the application of positive controls. In addition, the use of co-cultures with immune cells more adequately reflects the inflammatory response upon exposure to toxicants.

Abstract 3178: Up-regulation of GLI1 expression in drug resistant rhabdomyosarcoma (RMS) and Ewing sarcoma (EWS) cell lines

Abstract Outcome for pediatric patients with recurrent sarcomas remains poor. Therefore, understanding mechanisms that lead to drug resistance and ways to overcome drug resistance therapeutically are essential. Recent reports have suggested a role for the Hedgehog signaling pathway and its downstream mediator GLI1 in acquisition of a multidrug resistance phenotype in esophageal adenocarcinoma, glioblastoma, and myeloid leukemia. Since GLI1 is expressed in the majority of RMS and EWS cases, we hypothesized that GLI1 up-regulation occurs as cells become drug resistant in vitro and in vivo. We established vincristine (VCR) resistant RMS cell lines (Embryonal RMS: RD, Ruch-2; Alveolar RMS: Rh30, Rh41) by serial exposure to increasing concentrations of VCR. Drug-resistance was defined as an IC50 of ≥30 fold of the baseline that was established using parental cells. In addition, we obtained EWS cell lines, representing untreated cases (CHLA-9 and TC-32) and cases following recurrence (CHLA-258 and TC-71). We used an 86-gene cancer drug resistance PCR array (Qiagen), to characterize gene expression differences between the parental vs. VCR-resistant RMS cells lines and between the untreated and recurrent EWS cell lines. GLI1 expression was significantly increased (p≤0.05) in VCR-resistant alveolar RMS cell lines (Rh30 [2.3 fold], and Rh41 [10.3 fold]) compared with parental cells. Expression of 2 additional genes (MDR1 [13,307 fold in Rh30 and 1,755 fold in Rh41 cells] and MVP [2.4 fold in Rh30 and 8.8 fold in Rh41]) was also significantly up-regulated in these cells. Gel mobility shifts showed interaction of GLI1 with the MVP promoter, and cotransfection assays showed that GLI1 up-regulates reporter gene expression through the MVP promoter. GLI1 expression was significantly up-regulated in Ruch-2 embryonal RMS cells (2 fold). We also showed higher GLI1 expression in recurrent EWS cell lines (TC-71 [3.4 fold] and CHLA-258 [4.8 fold]) compared with untreated CHLA-9 cells. Expression of 1 additional gene (androgen receptor [11.1 fold in CHLA-258 cells and 274.6 fold in TC-71 cells]) was also significantly up-regulated in CHLA-258 and TC-71 cells. Treatment of VCR-resistant UKF Rhb-1 RMS cells with VCR together with either GANT61 or Cpd#33 (GLI1 inhibitors) significantly decreased cell viability by MTT assay at doses that did not reduce cell viability individually. Our results suggest that GLI1 up-regulation contributes to development of drug-resistance in RMS and EWS and that GLI1-inhibitors may reduce multidrug resistance. Citation Format: Joon Won Yoon, Iris Smith, Sumeed Manzoor, Marilyn Lamm, Philip Iannaccone, David Walterhouse. Up-regulation of GLI1 expression in drug resistant rhabdomyosarcoma (RMS) and Ewing sarcoma (EWS) cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3178.

Testosterone-mediated activation of androgenic signalling sustains in vitro the transformed and radioresistant phenotype of rhabdomyosarcoma cell lines.

Rhabdomyosarcoma (RMS), the most common soft-tissue sarcoma in childhood, rarely affects adults, preferring male. RMS expresses the receptor for androgen (AR) and responds to androgen; however, the molecular action of androgens on RMS is unknown. Herein, testosterone (T) effects were tested in embryonal (ERMS) and alveolar (ARMS) RMS cell lines, by performing luciferase reporter assay, RT-PCR, and western blotting experiments. RNA interference experiments or bicalutamide treatment was performed to assess the specific role of AR. Radiation treatment was delivered to characterise the effects of T treatment on RMS intrinsic radioresistance. Our study showed that RMS cells respond to sub-physiological levels of T stimulation, finally promoting AR-dependent genomic and non-genomic effects, such as the transcriptional regulation of several oncogenes, the phosphorylation-mediated post-transductional modifications of AR and the activation of ERK, p38 and AKT signal transduction pathway mediators that, by physically complexing or not with AR, participate in regulating its transcriptional activity and the expression of T-targeted genes. T chronic daily treatment, performed as for the hormone circadian rhythm, did not significantly affect RMS cell growth, but improved RMS clonogenic and radioresistant potential and increased AR mRNA both in ERMS and ARMS. AR protein accumulation was evident in ERMS, this further developing an intrinsic T-independent AR activity. Our results suggest that androgens sustain and improve RMS transformed and radioresistant phenotype, and therefore, their therapeutic application should be avoided in RMS post puberal patients.

Short communication: High incubation temperature in bovine mammary epithelial cells reduced the activity of the mTOR signaling pathway

Hyperthermia alters utilization of AA in protein synthesis and cell-signaling activity in bovine mammary cells. Essential AA and insulin regulate translation of proteins by controlling the activity of mammalian target of rapamycin (mTOR) signaling pathway. The objectives of this study were to evaluate (1) the effects of incubation temperature on the mTOR signaling pathway and transcription of AA transporters in a bovine mammary alveolar cell line (MAC-T) and (2) the combined effects of incubation temperature and insulin on the mTOR signaling pathway in this cell line. Cells were cultured in medium with 10% fetal bovine serum at 37°C and 5% CO2. In experiment 1, cells were subjected to 37°C (control) or 41.5°C (high incubation temperature; HT) for 12 h. In experiment 2, cells were assigned to 1 of 4 treatments as a 2 × 2 factorial arrangement, including 2 cell culture temperatures (control and HT) and absence or presence of 1.0 μg/mL of insulin. Proteins were harvested and separated by gel electrophoresis. In experiment 1, gene expression of AA transporters (SLC1A1, SLC1A5, SLC3A2, SLC7A1, SLC7A5, and SLC36A1) were evaluated, and changes of ≥2 fold were deemed significantly different. In experiments 1 and 2, immunoblotting was used to identify total and site-specific phosphorylated forms of protein kinase B (Akt1; Ser473), p70 S6 kinase (S6K1; Thr389), ribosomal protein S6 (rpS6; Ser235/236), and eukaryotic elongation factor 2 (eEF2; Thr56). Phosphorylated and total forms of Akt1, S6K1, rpS6, and eEF2 were quantified and expressed as the ratio of phosphorylated to total protein. In experiment 1, HT resulted in a ≥2-fold increase expression of SLC1A1 and SLC3A2. High incubation temperature reduced the phosphorylated to total ratio of Akt1 and rpS6 and increased the phosphorylated to total ratio of eEF2. In experiment 2, we found no temperature by insulin interactions on phosphorylation state of the protein factors of interest. High incubation temperature reduced the phosphorylated to total ratio of Akt1. The addition of insulin increased the phosphorylated to total ratio of Akt1, S6K1, and rpS6. In summary, HT reduced the activity of the mTOR signaling pathway and increased the expression of AA transporters. High incubation temperature possibly reduced protein translation by reducing the mTOR signaling pathway activity in an effort to adapt to thermal stress. These results may help explain the direct effect of elevated temperature on AA metabolism and protein translation in heat-stressed animals.

A novel retinoid X receptor agonist, UAB30, inhibits rhabdomyosarcoma cells in vitro

BackgroundWhile patients with early-stage rhabdomyosarcoma (RMS) have seen steady improvement in prognosis over the last 50 y, those with advanced-stage or high-grade disease continue to have a dismal prognosis. Retinoids have been shown to cause growth suppression and terminal differentiation in RMS cells, but the toxicities associated with retinoic acid limit its use. Rexinoids provide an alternative treatment approach to retinoic acid. Rexinoids primarily bind the retinoid X receptor with minimal retinoic acid receptor binding, the entity responsible for many of the toxicities of retinoid therapies. UAB30 is a novel rexinoid with limited toxicities. We hypothesized that UAB30 would lead to decreased cell survival in RMS. Materials and methodsTwo RMS cell lines, one embryonal (RD) subtype and one alveolar (St. Jude Cancer Research Hospital 30) subtype, were used. Cells were treated with UAB30, and cytotoxicity, proliferation, mobility, and apoptosis were evaluated. ResultsUAB30 significantly decreased RMS tumor cell viability and proliferation. Invasion, migration, and attachment-independent growth were reduced following UAB30 treatment. UAB30 also resulted in apoptosis and G1 cell cycle arrest. UAB30 affected both the alveolar and embryonal RMS cell lines in a similar fashion. ConclusionsThe results of these studies suggest a potential therapeutic role for the low-toxicity synthetic retinoid X receptor selective agonist, UAB30, in RMS treatment.

Abstract IA20: Autophagy in alveolar soft part sarcomagenesis

Abstract Altered metabolism is considered to be one of the new hallmarks of cancer. Autophagy is one major avenue of altered cancer metabolism, enabling cell survival under metabolic stress and promoting chemoresistance. The nuclear localization of MiTF/TFE3 family transcription factors has associated with upregulated transcription of autophagy genes in pancreatic cancer. Alveolar soft part sarcoma is a rare but deadly soft-tissue sarcoma, with a predilection for adolescent and young adult victims. Alveolar soft part sarcoma is noteworthy for its resistance to traditional cytotoxic chemotherapies. It consistently associates with a t(X;17) chromosomal translocation that produces the ASPSCR1-TFE3 target gene, bearing the DNA-binding domain from TFE3 and protein interaction domains from ASPSCR1. We have demonstrated that conditional expression of ASPSCR1-TFE3 is sufficient to drive alveolar soft part sarcomagenesis in the mouse with complete penetrance. Mouse tumors recapitulate human alveolar soft part sarcoma histology and transcriptomes faithfully. While direct targets of ASPSCR1-TFE3 have been studied in a renal cell carcinoma cell line, they have not been studied in alveolar soft part sarcoma. We report not only the first genome-wide localization of the ASPSCR1-TFE3 oncoprotein on chromatin from alveolar soft part sarcoma cell lines and mouse tumors, but also its association with actively transcribed genes. Among these are found many genes related to autophagy, especially those related specifically to the nutrient responsive pathways that drive autophagy. We demonstrate high expression of autophagy-related lysosomes and proteins at baseline conditions in human tumors and cell lines and mouse tumors. We also demonstrate active autophagic flux even in the absence of stress conditions. Inhibition of autophagy has no apparent impact on the survival of alveolar soft part sarcoma cells alone, but profoundly impacts their protein degradation pathways and the availability of amino acids for protein assembly in stress. Inhibition of autophagy strongly synergizes with chemotherapy to kill alveolar soft part sarcoma cells, suggesting it was a source mechanism for resistance. We have therefore demonstrated the direct targets of ASPSCR1-TFE3 in alveolar soft part sarcomas, including a number of autophagy genes that are expressed in these tumors, independently from nutrient deprivation or stress, rendering cells particularly resistant to many therapy-induced stresses. Citation Format: Kevin B. Jones. Autophagy in alveolar soft part sarcomagenesis [abstract]. In: Proceedings of the AACR Conference on Advances in Sarcomas: From Basic Science to Clinical Translation; May 16-19, 2017; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(2_Suppl):Abstract nr IA20.

Rational Design of Polypeptide‐Based Block Copolymer for Nonviral Gene Delivery

AbstractThe present work describes the development, characterization, and in vitro evaluation of novel poly(L‐lysine)‐based polyplexes as nonviral gene delivery systems. Initially, a well‐defined hybrid block copolymer comprising poly(ethylene glycol) methacrylate) (POEGMA) and poly(L‐lysine) (PLL) blocks was successfully synthesized and characterized. The hybrid copolymer shows high ability to condense DNA into stable polyplexes in aqueous media with sizes of approx. 100 nm. The nanoplexes were evaluated for cellular toxicity in A549 alveolar and HepG2 (hepatocarcinoma) cell lines. The nanoparticles cell internalization and transfection ability were assessed in HepG2 cells. The initial experiments showed that DNA was successfully transfected into the nucleus of human liver cancer cells and expressed enhanced green fluorescent protein (EGFP) gene with green fluorescence emission. These results revealed that the newly synthesized POEGMA‐b‐PLL diblock copolymer might be very attractive candidate as a nonviral gene delivery vector.

Exposure to selected limonene oxidation products: 4-OPA, IPOH, 4-AMCH induces oxidative stress and inflammation in human lung epithelial cell lines

Limonene oxidation products (LOPs) have gained interest on their harmful health effects over time. Recently, studies have shown that the selected LOPs: 4-oxopentanal (4-OPA), 3-isopropenyl-6-oxo-heptanal (IPOH) and 4-acetyl-1-methylcyclohexene (4-AMCH) have sensory irritation effects in mice and inflammatory effects in human lung cells. This study was therefore undertaken to investigate the potential capacity of 4-OPA, IPOH and 4-AMCH to cause cell membrane damage, oxidative stress and inflammation in human bronchial (16HBE14o-) and alveolar (A549) epithelial cell lines.Overall results suggest that 4-OPA, IPOH have cytotoxic effects on human lung cells that might be mediated by ROS: the highest concentration applied of IPOH [500 μM] enhanced ROS generation by 100-fold ± 7.7 (A549) and 230-fold ± 19.9 (16HBE14o-) compared to the baseline. 4-OPA [500 μM] increased ROS levels by 1.4-fold ± 0.3 (A549) and by 127-fold ± 10.5 (16HBE14o-), while treatment with 4-AMCH [500 μM] led to 0.9-fold ± 0.2 (A549) and 49-fold ± 12.8 (16HBE14o-) increase. IPOH [500 μM] caused a decrease in the thiol-state balance (e.g. after 2 h, GSH:GSSG was reduced by 37% compared to the untreated 16HBE14o-cells). 4-OPA [500 μM] decreased the GSH:GSSG by 1.3-fold change in A549 cells and 1.4-fold change in 16HBE14o-cells. No statistically significant decrease in the GSH:GSSG in A549 and 16HBE14o-cell lines was observed for 4-AMCH [500 μM]. In addition, IPOH and 4-OPA [31.2 μM] increased the amount of the inflammatory markers: RANTES, VEGF and EGF. On the other hand, 4-AMCH [31.2 μM] did not show inflammatory effects in A549 or 16HBE14o-cells.The 4-OPA, IPOH and 4-AMCH treatment concentration and time-dependently induce oxidative stress and/or alteration of inflammatory markers on human bronchial and alveolar cell lines.