Next generation thiazolyl ketone inhibitors of cytosolic phospholipase A α for targeted cancer therapy.

Eicosanoids are key players in inflammatory diseases and cancer. Targeting their production by inhibiting Group IVA cytosolic phospholipase A (cPLAα) offers a promising approach for cancer therapy. In this study, we synthesize a second generation of thiazolyl ketone inhibitors of cPLAα starting with compound GK470 (AVX235) and test their in vitro and cellular activities.

The effect of nasal douching by hypertonic 2.3 per cent sea water with algae extracts on the concentration of epidermal growth factor, transforming growth factor-α and interleukin-8 in nasal secretions of patients with nasal polyposis following endoscopic surgical treatment.

Objective: To investigate epidermal growth factor, transforming growth factor-α and interleukin-8 production in nasal mucosa irrigated with hypertonic 2.3 per cent solution with algae extracts, in comparison to 0.9 per cent NaCl during the first two weeks after surgery for nasal polyposis, in relation to symptoms and local findings.

ATX-101, a cell-penetrating protein targeting PCNA, can be safely administered as intravenous infusion in patients and shows clinical activity in a Phase 1 study.

Proliferating Cell Nuclear Antigen (PCNA) is a highly conserved protein essential for DNA replication, repair and scaffold functions in the cytosol. Specific inhibition of PCNA in cancer cells is an attractive anti-cancer strategy. ATX-101 is a first-in-class drug targeting PCNA, primarily in cellular stress regulation.

Efficacy and safety of a hypertonic seawater nasal irrigation solution containing algal and herbal natural ingredients in patients with COVID-19.

Objective: The objective of this study was to evaluate the efficacy and safety of using a hypertonic seawater nasal irrigation solution comprising natural ingredients (HSS-Plus) with the aim of reducing viral load and ameliorating nasal symptoms in cases of COVID-19.

Patients And Methods: This single-center, prospective, single-arm, low-intervention study evaluated daily use of HSS-Plus in patients admitted to the Sotiria Hospital, Athens, Greece for a period of up to 10 days or until hospital discharge. Viral load measurements in nasopharyngeal swabs were performed on days 0 (baseline), 3 and 6, and on the final day of participation (day 10 ± 2; hospital discharge).

Efficacy and safety of a hypertonic nasal wash solution containing sea algae extracts in patients that underwent surgical correction of a deviated nasal septum and radiofrequency turbinate volume reduction.

Objective: The objective of this study was to evaluate efficacy and safety of a Hypertonic Seawater Solution (2.3% NaCl) containing brown and blue-green Algae (HSS-A) in comparison to Isotonic Saline Solution (ISS) regarding the improvement of nasal breathing in patients that have undergone surgical correction of a deviated nasal septum and radiofrequency turbinate volume reduction.

Patients And Methods: A total of 101 individuals were enrolled in the study (HSS-A: 57; ISS: 44).

Effect of nasal irrigation on allergic rhinitis control in children; complementarity between CARAT and MASK outcomes.

Background: Nasal irrigations (NI) are increasingly used as an over-the-counter adjunctive treatment for allergic rhinitis (AR), but clinical studies on their effectiveness are limited.

Methods: An open-label, controlled, non-randomized, real-life study was conducted to evaluate the effectiveness of NI with a new hypertonic solution as add-on treatment for AR. Children and adolescents with AR were prescribed symptomatic treatment.

Istaroxime Inhibits Motility and Down-Regulates Orai1 Expression, SOCE and FAK Phosphorylation in Prostate Cancer Cells.

Background/aims: Istaroxime is a validated inotropic Na+/K+ ATPase inhibitor currently in development for the treatment of various cardiac conditions. Recent findings established that this steroidal drug exhibits potent apoptotic responses in prostate tumors in vitro and in vivo, by affecting key signaling orchestrating proliferation and apoptosis, such as c-Myc and caspase 3, Rho GTPases and actin cytoskeleton dynamics. In the present study we examined whether istaroxime is affecting cell motility and analyzed the underlying mechanism in prostate tumor cells.

Functional characterization and anti-cancer action of the clinical phase II cardiac Na+/K+ ATPase inhibitor istaroxime: in vitro and in vivo properties and cross talk with the membrane androgen receptor.

Sodium potassium pump (Na+/K+ ATPase) is a validated pharmacological target for the treatment of various cardiac conditions. Recent published data with Na+/K+ ATPase inhibitors suggest a potent anti-cancer action of these agents in multiple indications. In the present study, we focus on istaroxime, a Na+/K+ ATPase inhibitor that has shown favorable safety and efficacy properties in cardiac phase II clinical trials.

Membrane androgen receptor down-regulates c-src-activity and beta-catenin transcription and triggers GSK-3beta-phosphorylation in colon tumor cells.

Background/aims: Functional membrane androgen receptors (mARs) have recently been described in colon tumor cells and tissues. Their activation by specific testosterone albumin conjugates (TAC) down-regulates the PI-3K/Akt pro-survival signaling and triggers potent pro-apoptotic responses both, in vitro and in vivo. The present study explored the mAR-induced regulation of gene products implicated in the tumorigenic activity of Caco2 colon cancer cells.

Na+/K+ ATPase inhibitors in cancer.

Sodium potassium pump (Na(+)/K(+) ATPase) is a transmembrane protein complex found in all higher eukaryotes acting as a key energy-consuming pump maintaining ionic and osmotic balance in cells. Recently recognized as an important transducer and/or integrator of various signals as well as a protein-protein interaction scaffold forming receptor complexes with signaling properties, the most prominent pharmacological role of Na(+)/K(+) ATPase inhibitors is the increase of myocardial contractility in pathologic conditions such as congestive heart failure. Consequently, modulators of Na(+)/K(+) ATPase such as digoxin have been approved by regulatory authorities and are widely used in the treatment of cardiac failure since 1975.

A steroidal Na+/K+ ATPase inhibitor triggers pro-apoptotic signaling and induces apoptosis in prostate and lung tumor cells.

Recently we have reported potent anti-cancer actions of various steroidal Na(+)/K(+) ATPase inhibitors in multiple cell lines. Furthermore, the most powerful compound identified in this study, the 3-[(R)-3-pyrrolidinyl]oxime derivative (3-R-POD), was highly effective in various tumor cell lines in vitro, and exhibited significant tumor growth inhibition in prostate and lung xenografts in vivo. In the present study we have addressed the molecular mechanisms implicated in the anti-cancer actions of 3-R-POD.

Steroidal cardiac Na+/K+ ATPase inhibitors exhibit strong anti-cancer potential in vitro and in prostate and lung cancer xenografts in vivo.

Sodium potassium pump (Na(+)/K(+)ATPase) is a validated pharmacological target for the treatment of congestive heart failure. Recent data with inotropic drugs such as digoxin & digitoxin (digitalis) suggest a potent anti-cancer action of these drugs and promote Na(+)/K(+)ATPase as a novel therapeutic target in cancer. However, digitalis have narrow therapeutic indices, are pro-arrhythmic and are considered non-developable drugs by the pharmaceutical industry.

Targeting membrane androgen receptors in tumors.

Introduction: In the last decade androgen actions that are originated from non-genomic, rapid signaling have been described in a large number of cell models and tissues. These effects are initiated through the stimulation of membrane androgen-binding sites or receptors (mAR). Although the molecular identity of mARs remains elusive, their activation is known to trigger multiple non-genomic signaling cascades and to regulate numerous cell responses.

Rapid activation of FAK/mTOR/p70S6K/PAK1-signaling controls the early testosterone-induced actin reorganization in colon cancer cells.

Actin cytoskeleton reorganization initiated by testosterone conjugates through activation of membrane androgen receptors (mAR) has recently been reported in colon tumor cells. This mAR-induced actin reorganization was recognized as a critical initial event, controlling apoptosis and inhibiting cell migration. The present study addressed the molecular signaling regulating the rapid actin remodeling initiated upon testosterone-induced mAR activation in Caco2 colon tumor cells.

Serum- and glucocorticoid-dependent kinase-1-induced cell migration is dependent on vinculin and regulated by the membrane androgen receptor.

The serum- and glucocorticoid-dependent kinases 1-3 (SGK1-3) are downstream effectors of phosphatidylinositol 3-kinases, implicated in various cell responses including colon cancer tumorigenesis in mice. Here, we investigated the role of SGK1 in the regulation of cell motility. Using Caco-2 colon tumor and HEK293 embryonic kidney cells, we report that transfection with the constitutively active SGK1 mutant (SGK1-SD) significantly enhanced cell motility.

The labdane diterpene sclareol (labd-14-ene-8, 13-diol) induces apoptosis in human tumor cell lines and suppression of tumor growth in vivo via a p53-independent mechanism of action.

The labdane diterpene sclareol has demonstrated significant cytotoxicity against human tumor cell lines and human colon cancer xenografts. Therefore, there is need to elucidate the mode of action of this compound as very little information is known for the anticancer activity of sclareol and other labdane diterpenes, in general. COMPARE analysis of GI(50) values for a number of human cancer cell lines was initially implicated in an effort to assign a putative mechanism of action to the compound.

Activation of membrane androgen receptors in colon cancer inhibits the prosurvival signals Akt/bad in vitro and in vivo and blocks migration via vinculin/actin signaling.

Recently, we reported that membrane androgen receptors (mARs) are expressed in colon tumors triggering strong apoptotic responses. In the present study, we analyzed mAR-induced downstream effectors controlling cell survival and migration of Caco2 colon cancer cells. We show that long-term activation of mAR downregulated the activity of PI-3K and Akt and induced de-phosphorylation/activation of the proapoptotic Bad (p-Bad).

Functional membrane androgen receptors in colon tumors trigger pro-apoptotic responses in vitro and reduce drastically tumor incidence in vivo.

Background: Membrane androgen receptors (mAR) have been implicated in the regulation of cell growth, motility and apoptosis in prostate and breast cancer. Here we analyzed mAR expression and function in colon cancer.

Results: Using fluorescent mAR ligands we showed specific membrane staining in colon cell lines and mouse xenograft tumor tissues, while membrane staining was undetectable in healthy mouse colon tissues and non-transformed intestinal cells.

Membrane androgen receptor activation in prostate and breast tumor cells: molecular signaling and clinical impact.

In recent years, membrane androgen receptors (mARs) have been identified in prostate and breast tumor cells, and their activation by specific mAR ligands was linked to the regulation of crucial cell responses, such as cell growth, motility, and apoptosis. Analysis of the molecular signals triggered by mAR in the presence of anti-androgens has clearly differentiated mAR-dependent biological actions from those induced by the activation of the classical intracellular androgen receptors (iARs). In this review, we summarize the specific cellular events attributed to mAR activation and the experimental results on distinct non-genomic signaling cascades operating in various tumor cells independently of the iAR.

Membrane androgen receptor activation triggers down-regulation of PI-3K/Akt/NF-kappaB activity and induces apoptotic responses via Bad, FasL and caspase-3 in DU145 prostate cancer cells.

Background: Recently we have reported membrane androgen receptors-induced apoptotic regression of prostate cancer cells regulated by Rho/ROCK/actin signaling. In the present study we explored the specificity of these receptors and we analyzed downstream effectors controlling survival and apoptosis in hormone refractory DU145-prostate cancer cells stimulated with membrane androgen receptor-selective agonists.

Results: Using membrane impermeable conjugates of serum albumin covalently linked to testosterone, we show here down-regulation of the activity of pro-survival gene products, namely PI-3K/Akt and NF-kappaB, in DU145 cells.

Rho/ROCK/actin signaling regulates membrane androgen receptor induced apoptosis in prostate cancer cells.

In this study we describe a novel Rho small GTPase dependent pathway that elicits apoptotic responses controlled by actin reorganization in hormone-sensitive LNCaP- and hormone insensitive DU145-prostate cancer cells stimulated with membrane androgen receptor selective agonists. Using an albumin-conjugated steroid, testosterone-BSA, we now show significant induction of actin polymerization and apoptosis that can be reversed by actin disrupting agents in both cell lines. Testosterone-BSA triggered RhoA/B and Cdc42 activation in DU145 cells followed by stimulation of downstream effectors ROCK, LIMK2 and ADF/destrin.

Sclareol induces apoptosis in human HCT116 colon cancer cells in vitro and suppression of HCT116 tumor growth in immunodeficient mice.

Labd-14-ene-8, 13-diol (sclareol) is a labdane-type diterpene, which has demonstrated significant cytotoxic activity against human leukemic cell lines, but its effect on solid tumor-derived cells is uknown. Here, we demonstrate that addition of sclareol to cultures of human colon cancer HCT116 cells results in inhibition of DNA synthesis, arrest of cells at the G(1) phase of the cell cycle, activation of caspases-8, -9, PARP degradation, and DNA fragmentation, events characteristic of induction of apoptosis. Intraperitoneal (ip) administration of sclareol alone, at the maximum tolerated dose, was unable to induce suppression of growth of HCT116 tumors established as xenografts in immunodeficient SCID mice.

Labd-14-ene-8,13-diol (sclareol) induces cell cycle arrest and apoptosis in human breast cancer cells and enhances the activity of anticancer drugs.

Sclareol is a labdane-type diterpene that has demonstrated a significant cytotoxic activity against human leukemic cell lines. Here, we report the effect of sclareol against the human breast cancer cell lines MN1 and MDD2 derived from the parental cell line, MCF7. MN1 cells express functional p53, whereas MDD2 cells do not express p53.

Recruitment of TRRAP required for oncogenic transformation by E1A.

TRRAP links Myc with histone acetylases and appears to be an important mediator of its oncogenic function. Here we show that interaction with TRRAP is required for cellular transformation not only by Myc, but also by the adenovirus E1A protein. Substitution of the 262 N-terminal residues of Myc with a small domain of E1A (residues 12-54) restores Myc transforming function.

NF-kappaB signals induce the expression of c-FLIP.

Activation of the transcription factor NF-kappaB is a major effector of the inducible resistance to death receptor-mediated apoptosis. Previous evidence indicates that the combined transcriptional activation of TRAF-1, TRAF-2, IAP-1, and IAP-2 is required to suppress cell death by tumor necrosis factor (TNF). Here we show that NF-kappaB activation upregulates the caspase 8 inhibitor FLIP, resulting in increased resistance to Fas ligand (FasL) or TNF.