Mechanistic Insights Behind the Self-Assembly of Human Insulin under the Influence of Surface-Engineered Gold Nanoparticles.

Elucidating the underlying principles of amyloid protein self-assembly at nanobio interfaces is extremely challenging due to the diversity in physicochemical properties of nanomaterials and their physical interactions with biological systems. It is, therefore, important to develop nanoscale materials with dynamic features and heterogeneities. In this work, through engineering of hierarchical polyethylene glycol (PEG) structures on gold nanoparticle (GNP) surfaces, tailored nanomaterials with different surface properties and conformations (GNPs-PEG) are created for modulating the self-assembly of a widely studied protein, insulin, under amyloidogenic conditions. Important biophysical studies including thioflavin T (ThT) binding, circular dichroism (CD), surface plasmon resonance (SPR), and atomic force microscopy (AFM) showed that higher-molecular weight GNPs-PEG triggered the formation of amyloid fibrils by promoting adsorption of proteins at nanoparticle surfaces and favoring primary nucleation rate. Moreover, the modulation of fibrillation kinetics reduces the overall toxicity of insulin oligomers and fibrils. In addition, the interaction between the PEG polymer and amyloidogenic insulin examined using MD simulations revealed major changes in the secondary structural elements of the B chain of insulin. The experimental findings provide molecular-level descriptions of how the PEGylated nanoparticle surface modulates protein adsorption and drives the self-assembly of insulin. This facile approach provides a new avenue for systematically altering the binding affinities on nanoscale surfaces by tailoring their topologies for examining adsorption-induced fibrillogenesis phenomena of amyloid proteins. Together, this study suggests the role of nanobio interfaces during surface-induced heterogeneous nucleation as a primary target for designing therapeutic interventions for amyloid-related neurodegenerative disorders.

Selective targeting of IRAK1 attenuates low molecular weight hyaluronic acid-induced stemness and non-canonical STAT3 activation in epithelial ovarian cancer.

Advanced epithelial ovarian cancer (EOC) survival rates are dishearteningly low, with ~25% surviving beyond 5 years. Evidence suggests that cancer stem cells contribute to acquired chemoresistance and tumor recurrence. Here, we show that IRAK1 is upregulated in EOC tissues, and enhanced expression correlates with poorer overall survival. Moreover, low molecular weight hyaluronic acid, which is abundant in malignant ascites from patients with advanced EOC, induced IRAK1 phosphorylation leading to STAT3 activation and enhanced spheroid formation. Knockdown of IRAK1 impaired tumor growth in peritoneal disease models, and impaired HA-induced spheroid growth and STAT3 phosphorylation. Finally, we determined that TCS2210, a known inducer of neuronal differentiation in mesenchymal stem cells, is a selective inhibitor of IRAK1. TCS2210 significantly inhibited EOC growth in vitro and in vivo both as monotherapy, and in combination with cisplatin. Collectively, these data demonstrate IRAK1 as a druggable target for EOC.

Fluorinated and N-Acryloyl-Modified 3,5-Di[(E)-benzylidene]piperidin-4-one Curcuminoids for the Treatment of Pancreatic Carcinoma.

Pancreatic carcinoma is a cancer disease with high mortality. Thus, new and efficient treatments for this disease are badly needed. Curcumin has previously shown promising effects in pancreatic cancer patients; however, this natural compound suffers from inadequate efficacy and bioavailability, preventing its clinical approval. The synthetic curcuminoid EF24 was developed with activities superior to curcumin against various cancer types. In this study, a series of analogs of EF24 were investigated for anticancer effects on pancreatic carcinoma models. A distinct activity boost was achieved by straightforward N-acrylation of EF24 analogs, in particular, of compounds bearing 3-fluoro-4-methoxybenzylidene, 3,4-difluorobenzylidene, and 4-trifluoromethylbenzylidene moieties, while no improvement was seen for N-acryloyl-modified EF24. Apoptosis induction and suppression of phospho-STAT3 levels were determined, the latter corroborated by docking of active curcuminoids into STAT3. Hence, promising new clues for the development of efficient and superior curcuminoids as valuable treatment options for one of the most lethal cancer diseases were discovered in this study.

Anticancer Activity of Novel Difluorinated Curcumin Analog and Its Inclusion Complex with 2-Hydroxypropyl-ß-Cyclodextrin against Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is the primary reason for cancer-related deaths in the US. Genetic mutations, drug resistance, the involvement of multiple signaling pathways, cancer stem cells (CSCs), and desmoplastic stroma, which hinders drug penetrance, contribute to poor chemotherapeutic efficacy. Hence, there is a need to identify novel drugs with improved delivery to improve treatment outcomes. Curcumin is one such compound that can inhibit multiple signaling pathways and CSCs. However, curcumin's clinical applicability for treating PDAC is limited because of its poor solubility in water and metabolic instability. Hence, we developed a difluorinated curcumin (CDF) analog that accumulates selectively in the pancreas and inhibits PDAC growth in vitro and in vivo. In the present work, we developed its 2-hydroxy-propyl-ß-cyclodextrin (HCD) inclusion complex to increase its water solubility and hydrolytic stability. The CDFHCD inclusion complex was characterized by spectroscopic, thermal, and microscopic techniques. The inclusion complex exhibited increased aqueous solubility, hydrolytic stability, and antiproliferative activity compared to parent CDF. Moreover, CDF and CDFHCD inhibited colony and spheroid formation, and induced cell cycle and apoptosis in PDAC cell lines. Hence, CDFHCD self-assembly is an efficient approach to increase water solubility and anticancer therapeutic efficacy, which now warrants advancement towards a clinical proof of concept in PDAC patients.

New 4,5-Diarylimidazol-2-ylidene-iodidogold(I) Complexes with High Activity against Esophageal Adenocarcinoma Cells.

Inspired by the vascular-disrupting agent combretastatin A-4 and recently published anticancer active N-heterocyclic carbene (NHC) complexes of Au(I), a series of new iodidogold(I)-NHC complexes was synthesized and characterized. The iodidogold(I) complexes were synthesized by a route involving van Leusen imidazole formation and N-alkylation, followed by complexation with Ag2O, transmetalation with chloro(dimethylsulfide)gold(I) [Au(DMS)Cl], and anion exchange with KI. The target complexes were characterized by IR spectroscopy, 1H and 13C NMR spectroscopy, and mass spectrometry. The structure of 6c was validated via single-crystal X-ray diffraction. A preliminary anticancer screening of the complexes using two esophageal adenocarcinoma cell lines showed promising nanomolar activities for certain iodidogold(I) complexes accompanied with apoptosis induction, as well as c-Myc and cyclin D1 suppression in esophageal adenocarcinoma cells treated with the most promising derivative 6b.

Synthesis and Anticancer Evaluation of New Indole-Based Tyrphostin Derivatives and Their (p-Cymene)dichloridoruthenium(II) Complexes.

New N-alkylindole-substituted 2-(pyrid-3-yl)-acrylonitriles with putative kinase inhibitory activity and their (p-cymene)Ru(II) piano-stool complexes were prepared and tested for their antiproliferative efficacy in various cancer models. Some of the indole-based derivatives inhibited tumor cell proliferation at (sub-)micromolar concentrations with IC50 values below those of the clinically relevant multikinase inhibitors gefitinib and sorafenib, which served as positive controls. A focus was set on the investigation of drug mechanisms in HCT-116 p53-knockout colon cancer cells in order to evaluate the dependence of the test compounds on p53. Colony formation assays as well as experiments with tumor spheroids confirmed the excellent antineoplastic efficacy of the new derivatives. Their mode of action included an induction of apoptotic caspase-3/7 activity and ROS formation, as well as anti-angiogenic properties. Docking calculations with EGFR and VEGFR-2 identified the two 3-aryl-2-(pyrid-3-yl)acrylonitrile derivatives 2a and 2b as potential kinase inhibitors with a preferential activity against the VEGFR-2 tyrosine kinase. Forthcoming studies will further unveil the underlying mode of action of the promising new derivatives as well as their suitability as an urgently needed novel approach in cancer treatment.

Doublecortin-like kinase 1 is a therapeutic target in squamous cell carcinoma.

Doublecortin like kinase 1 (DCLK1) plays a crucial role in several cancers including colon and pancreatic adenocarcinomas. However, its role in squamous cell carcinoma (SCC) remains unknown. To this end, we examined DCLK1 expression in head and neck SCC (HNSCC) and anal SCC (ASCC). We found that DCLK1 is elevated in patient SCC tissue, which correlated with cancer progression and poorer overall survival. Furthermore, DCLK1 expression is significantly elevated in human papilloma virus negative HNSCC, which are typically aggressive with poor responses to therapy. To understand the role of DCLK1 in tumorigenesis, we used specific shRNA to suppress DCLK1 expression. This significantly reduced tumor growth, spheroid formation, and migration of HNSCC cancer cells. To further the translational relevance of our studies, we sought to identify a selective DCLK1 inhibitor. Current attempts to target DCLK1 using pharmacologic approaches have relied on nonspecific suppression of DCLK1 kinase activity. Here, we demonstrate that DiFiD (3,5-bis [2,4-difluorobenzylidene]-4-piperidone) binds to DCLK1 with high selectivity. Moreover, DiFiD mediated suppression of DCLK1 led to G2/M arrest and apoptosis and significantly suppressed tumor growth of HNSCC xenografts and ASCC patient derived xenografts, supporting that DCLK1 is critical for SCC growth.

SHP2 regulates adipose maintenance and adipocyte-pancreatic cancer cell crosstalk via PDHA1.

Adipocytes are the most abundant cell type in the adipose tissue, and their dysfunction is a significant driver of obesity-related pathologies, such as cancer. The mechanisms that (1) drive the maintenance and secretory activity of adipocytes and (2) mediate the cancer cellular response to the adipocyte-derived factors are not fully understood. To address that gap of knowledge, we investigated how alterations in Src homology region 2-containing protein (SHP2) activity affect adipocyte function and tumor crosstalk. We found that phospho-SHP2 levels are elevated in adipose tissue of obese mice, obese patients, and differentiating adipocytes. Immunofluorescence and immunoprecipitation analyses as well as in-silico protein-protein interaction modeling demonstrated that SHP2 associates with PDHA1, and that a positive association promotes a reactive oxygen species (ROS)-driven adipogenic program. Accordingly, this SHP2-PDHA1-ROS regulatory axis was crucial for adipocyte maintenance and secretion of interleukin-6 (IL-6), a key cancer-promoting cytokine. Mature adipocytes treated with an inhibitor for SHP2, PDHA1, or ROS exhibited an increased level of pro-lipolytic and thermogenic proteins, corresponding to an increased glycerol release, but a suppression of secreted IL-6. A functional analysis of adipocyte-cancer cell crosstalk demonstrated a decreased migration, invasion, and a slight suppression of cell cycling, corresponding to a reduced growth of pancreatic cancer cells exposed to conditioned media (CM) from mature adipocytes previously treated with inhibitors for SHP2/PDHA1/ROS. Importantly, PDAC cell growth stimulation in response to adipocyte CM correlated with PDHA1 induction but was suppressed by a PDHA1 inhibitor. The data point to a novel role for (1) SHP2-PDHA1-ROS in adipocyte maintenance and secretory activity and (2) PDHA1 as a regulator of the pancreatic cancer cells response to adipocyte-derived factors.

Prolactin receptor signaling: A novel target for cancer treatment - Exploring anti-PRLR signaling strategies.

Prolactin (PRL) is a peptide hormone mainly secreted from the anterior pituitary gland. PRL is reported to play a role in pregnancy, mammary gland development, immune modulation, reproduction, and differentiation of islet cells. PRL binds to its receptor PRLR, which belongs to a superfamily of the class I cytokine receptor that has no intrinsic kinase activity. In canonical signaling, PRL binding to PRLR induces downstream signaling including JAK-STAT, AKT and MAPK pathways. This leads to increased cell proliferation, stemness, migration, apoptosis inhibition, and resistance to chemotherapy. PRL-signaling is upregulated in numerous hormone-dependent cancers including breast, prostate, ovarian, and endometrial cancer. However, more recently, the pathway has been reported to play a tumor-promoting role in other cancer types such as colon, pancreas, and hepatocellular cancers. Hence, the signaling pathway is an attractive target for drug development with blockade of the receptor being a potential therapeutic approach. Different strategies have been developed to target this receptor including modification of PRL peptides (Del1-9-G129R-hPRL, G129R-Prl), growth hormone receptor/prolactin receptor bispecific antibody antagonist, neutralizing antibody LFA102, an antibody-drug conjugate (ABBV-176) of the humanized antibody h16f (PR-1594804) and pyrrolobenzodiazepine dimer, a bispecific antibody targeting both PRLR and CD3, an in vivo half-life extended fusion protein containing PRLR antagonist PrlRA and albumin binding domain. There have also been attempts to discover and develop small molecular inhibitors targeting PRLR. Recently, using structure-based virtual screening, we identified a few antipsychotic drugs including penfluridol as a molecule that inhibits PRL-signaling to inhibit PDAC tumor progression. In this review, we will summarize the recent advances in the biology of this receptor in cancer and give an account of PRLR antagonist development for the treatment of cancer.

Enhanced IFNα Signaling Promotes Ligand-Independent Activation of ERα to Promote Aromatase Inhibitor Resistance in Breast Cancer.

Aromatase inhibitors (AIs) reduce estrogen levels up to 98% as the standard practice to treat postmenopausal women with estrogen receptor-positive (ER+) breast cancer. However, approximately 30% of ER+ breast cancers develop resistance to treatment. Enhanced interferon-alpha (IFNα) signaling is upregulated in breast cancers resistant to AIs, which drives expression of a key regulator of survival, interferon-induced transmembrane protein 1 (IFITM1). However, how upregulated IFNα signaling mediates AI resistance is unknown. In this study, we utilized MCF-7:5C cells, a breast cancer cell model of AI resistance, and demonstrate that these cells exhibit enhanced IFNα signaling and ligand-independent activation of the estrogen receptor (ERα). Experiments demonstrated that STAT1, the mediator of intracellular signaling for IFNα, can interact directly with ERα. Notably, inhibition of IFNα signaling significantly reduced ERα protein expression and ER-regulated genes. In addition, loss of ERα suppressed IFITM1 expression, which was associated with cell death. Notably, chromatin immunoprecipitation experiments validated that both ERα and STAT1 associate with ERE sequences in the IFITM1 promoter. Overall, hyperactivation of IFNα signaling enhances ligand-independent activation of ERα, which promotes ER-regulated, and interferon stimulated gene expression to promote survival in AI-resistant breast cancer cells.

Honokiol Affects Stem Cell Viability by Suppressing Oncogenic YAP1 Function to Inhibit Colon Tumorigenesis.

Honokiol (HNK) is a biphenolic compound that has been used in traditional medicine for treating various ailments, including cancers. In this study, we determined the effect of HNK on colon cancer cells in culture and in a colitis-associated cancer model. HNK treatment inhibited proliferation and colony formation while inducing apoptosis. In addition, HNK suppressed colonosphere formation. Molecular docking suggests that HNK interacts with reserve stem cell marker protein DCLK1, with a binding energy of -7.0 Kcal/mol. In vitro kinase assays demonstrated that HNK suppressed the DCLK1 kinase activity. HNK also suppressed the expression of additional cancer stem cell marker proteins LGR5 and CD44. The Hippo signaling pathway is active in intestinal stem cells. In the canonical pathway, YAP1 is phosphorylated at Ser127 by upstream Mst1/2 and Lats1/2. This results in the sequestration of YAP1 in the cytoplasm, thereby not allowing YAP1 to translocate to the nucleus and interact with TEAD1-4 transcription factors to induce gene expression. However, HNK suppressed Ser127 phosphorylation in YAP1, but the protein remains sequestered in the cytoplasm. We further determined that this occurs by YAP1 interacting with PUMA. To determine if this also occurs in vivo, we performed studies in an AOM/DSS induced colitis-associated cancer model. HNK administered by oral gavage at a dose of 5mg/kg bw for 24 weeks demonstrated a significant reduction in the expression of YAP1 and TEAD1 and in the stem marker proteins. Together, these data suggest that HNK prevents colon tumorigenesis in part by inducing PUMA-YAP1 interaction and cytoplasmic sequestration, thereby suppressing the oncogenic YAP1 activity.

Fosciclopirox suppresses growth of high-grade urothelial cancer by targeting the γ-secretase complex.

Ciclopirox (CPX) is an FDA-approved topical antifungal agent that has demonstrated preclinical anticancer activity in a number of solid and hematologic malignancies. Its clinical utility as an oral anticancer agent, however, is limited by poor oral bioavailability and gastrointestinal toxicity. Fosciclopirox, the phosphoryloxymethyl ester of CPX (Ciclopirox Prodrug, CPX-POM), selectively delivers the active metabolite, CPX, to the entire urinary tract following parenteral administration. We characterized the activity of CPX-POM and its major metabolites in in vitro and in vivo preclinical models of high-grade urothelial cancer. CPX inhibited cell proliferation, clonogenicity and spheroid formation, and increased cell cycle arrest at S and G0/G1 phases. Mechanistically, CPX suppressed activation of Notch signaling. Molecular modeling and cellular thermal shift assays demonstrated CPX binding to γ-secretase complex proteins Presenilin 1 and Nicastrin, which are essential for Notch activation. To establish in vivo preclinical proof of principle, we tested fosciclopirox in the validated N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) mouse bladder cancer model. Once-daily intraperitoneal administration of CPX-POM for four weeks at doses of 235 mg/kg and 470 mg/kg significantly decreased bladder weight, a surrogate for tumor volume, and resulted in a migration to lower stage tumors in CPX-POM treated animals. This was coupled with a reduction in the proliferation index. Additionally, there was a reduction in Presenilin 1 and Hes-1 expression in the bladder tissues of CPX-POM treated animals. Following the completion of the first-in-human Phase 1 trial (NCT03348514), the pharmacologic activity of fosciclopirox is currently being characterized in a Phase 1 expansion cohort study of muscle-invasive bladder cancer patients scheduled for cystectomy (NCT04608045) as well as a Phase 2 trial of newly diagnosed and recurrent urothelial cancer patients scheduled for transurethral resection of bladder tumors (NCT04525131).

Association of losartan with outcomes in metastatic pancreatic cancer patients treated with chemotherapy.

BACKGROUND: Previous trials have shown improved efficacy of neoadjuvant treatment when combined with angiotensin II receptor antagonist, losartan in patients with locally advanced pancreatic ductal adenocarcinoma (PDA). However, role of losartan is unknown in metastatic PDA. In this retrospective observational study, we examined the relationship between losartan use at time of diagnosis and continued through chemotherapy treatment with clinical outcomes in patients with metastatic PDA that received chemotherapy. METHODS: We retrospectively evaluated 114 metastatic PDA patients treated at University of Kansas Cancer Center between January 2000 and November 2019. We compared overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR) between patients using losartan at time of their cancer diagnosis and a control group of patients who were not on losartan. A subgroup analysis was performed based on patients who were on a 100 mg dose of losartan along with chemotherapy versus patients treated with chemotherapy (without losartan). Another subgroup analysis was performed based on chemotherapy regimen: Fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFIRINOX) versus Gemcitabine and Abraxane. RESULTS: No significant difference was found in OS (p=0.466) or PFS (p=0.919) in patients on losartan (median 274 day, 83 day) and control patients (median 279 day, 111 day). No significant difference was found in ORR (p=0.621) or in DCR (p=0.497). No significant difference was found in OS (p=0.771) or PFS (p=0.0604) in losartan patients (median 347 day, 350 day) and control patients (median 333 day, 101 day) treated with FOLFIRINOX. No significant difference was found in OS (p=0.916) or PFS (p=0.341) in losartan (median 312 day, 69 day) and control patients (median 221 day, 136 day) treated with Gemcitabine plus Abraxane. No significant difference was found in OS (p=0.727) or PFS (p=0.790) in 100 mg losartan patients (median 261 day, 84 day) and control (median 279 day, 111 day). CONCLUSIONS: Patients on losartan at time of diagnosis and continued through chemotherapy treatment had no significant difference in OS, PFS, ORR, DCR than control patients. Subgroup analysis of patients treated with FOLFIRINOX revealed a longer PFS with losartan than control but did not reach statistical significance, likely due to small sample size. Our findings should be validated in a larger cohort to confirm if the benefit of losartan and FOLFIRINOX seen in a neoadjuvant setting for locally advanced cancer also applies to metastatic cancer. RELEVANCE FOR PATIENTS: This research adds to growing data on the efficacy of angiotensin receptor blocking drugs as adjunctive treatment in addition to chemotherapy in pancreatic cancer with specific focus on metastatic disease.

Celastrol and Triptolide Suppress Stemness in Triple Negative Breast Cancer: Notch as a Therapeutic Target for Stem Cells.

Triple negative breast cancer (TNBC) is observed in ~15% of breast cancers and results in poor survival and increased distant metastases. Within the tumor are present a small portion of cancer stem cells that drive tumorigenesis and metastasis. In this study, we aimed to elucidate whether the two natural compounds, celastrol and triptolide, inhibit stemness in TNBC. MDA-MB-231, BT20, and a patient-derived primary cells (PD-TNBC) were used in the study. Mammosphere assay was performed to assess the stemness. Both celastrol and triptolide treatment suppressed mammosphere formation. Furthermore, the compound suppressed expression of cancer stem cell marker proteins DCLK1, ALDH1, and CD133. Notch signaling plays a critical role in stem cells renewal. Both celastrol or triptolide reduced Notch -1 activation and expression of its downstream target proteins HES-1 and HEY-1. However, when NICD 1 was ectopically overexpressed in the cells, it partially rescued proliferation and mammosphere formation of the cells, supporting the role of notch signaling. Together, these data demonstrate that targeting stem cells and the notch signaling pathway may be an effective strategy for curtailing TNBC progression.

A Bimodal Nanosensor for Probing Influenza Fusion Protein Activity Using Magnetic Relaxation.

Viral fusion is a critical step in the entry pathway of enveloped viruses and remains a viable target for antiviral exploration. The current approaches for studying fusion mechanisms include ensemble fusion assays, high-resolution cryo-TEM, and single-molecule fluorescence-based methods. While these methods have provided invaluable insights into the dynamic events underlying fusion processes, they come with their own limitations. These often include extensive data and image analysis in addition to experimental time and technical requirements. This work proposes the use of the spin-spin T2 relaxation technique as a sensitive bioanalytical method for the rapid quantification of interactions between viral fusion proteins and lipids in real time. In this study, new liposome-coated iron oxide nanosensors (LIONs), which mimic as magnetic-labeled host membranes, are reported to detect minute interactions occurring between the membrane and influenza's fusion glycoprotein, hemagglutinin (HA). The influenza fusion protein's interaction with the LION membrane is detected by measuring changes in the sensitive spin-spin T2 magnetic relaxation time using a bench-top NMR instrument. More data is gleaned from including the fluorescent dye DiI into the LION membrane. In addition, the effects of environmental factors on protein-lipid interaction that affect fusion such as pH, time of incubation, trypsin, and cholesterol were also examined. Furthermore, the efficacy and sensitivity of the spin-spin T2 relaxation assay in quantifying similar protein/lipid interactions with more native configurations of HA were demonstrated using virus-like particles (VLPs). Shorter domains derived from HA were used to start a reductionist path to identify the parts of HA responsible for the NMR changes observed. Finally, the known fusion inhibitor Arbidol was employed in our spin-spin T2 relaxation-based fusion assay to demonstrate the application of LIONs in real-time monitoring of this aspect of fusion for evaluation of potential fusion inhibitors.

Anticancer Active Heterocyclic Chalcones: Recent Developments.

BACKGROUND: Chalcones are structurally simple compounds that are easily accessible by synthetic methods. Heterocyclic chalcones have gained the interest of scientists due to their diverse biological activities. The anti-tumor activities of heterocyclic chalcones are especially remarkable and the growing number of publications dealing with this topic warrants an up-to-date compilation. METHODS: Search for antitumor active heterocyclic chalcones was carried out using Pubmed and Scifinder as common web-based literature searching tools. Pertinent and current literature was covered from 2015/2016 to 2019. Chemical structures, biological activities and modes of action of anti-tumor active heterocyclic chalcones are summarized. RESULTS: Simply prepared chalcones have emerged over the last years with promising antitumor activities. Among them, there are a considerable number of tubulin polymerization inhibitors. But there are also new chalcones targeting special enzymes such as histone deacetylases or with DNA-binding properties. CONCLUSION: This review provides a summary of recent heterocyclic chalcone derivatives with distinct antitumor activities.

Targeting Major Signaling Pathways of Bladder Cancer with Phytochemicals: A Review.

Bladder cancer is the 9th most prevalent cancer worldwide and carries a protracted treatment course with significant patient expense, morbidity, and mortality. Over 95% of bladder cancers arise from the urothelium and invade into the underlying muscle layer before metastasizing. Trans-urethral resection and BCG therapy is the current first-line treatment for non-muscle invasive bladder cancer but carries a high rate of tumor recurrence and progression. The poor outcomes associated with advanced disease indicate the urgent need for new and improved treatment strategies. There is increasing investigation into the molecular signaling pathways involved in bladder cancer pathogenesis with the goal of uncovering potential therapeutic targets. This article reviews the major signaling pathways implicated in bladder cancer, including PI3K/AKT/mTOR, Ras/Raf/MEK/MAPK, NF-κB, Wnt/ß-catenin, Notch, Hedgehog, Hippo, JAK/STAT, and TGF-ß as well as major cellular receptors central to cancer pathophysiology, including EGFR, Her2, FGFR, and VEGF. We also discuss various naturally occurring phytochemicals that show evidence of targeting these molecular pathways including curcumin, resveratrol, green tea polyphenols, sulforaphane, erucin, genistein, genipin, baicalein, quercetin, isoquercitin, vitamin E, parthenolide, dioscin, triptolide, kaempferol, pterostilbene, isoliquiritigenin, and escin. This review highlights the potential use of these compounds in treatment of bladder cancer.

Survival Outcomes of Pancreatic Intraepithelial Neoplasm (PanIN) versus Intraductal Papillary Mucinous Neoplasm (IPMN) Associated Pancreatic Adenocarcinoma.

Pancreatic intraepithelial neoplasms (PanINs) and intraductal papillary mucinous neoplasms (IPMNs) are common pancreatic adenocarcinoma precursor lesions. However, data regarding their respective associations with survival rate and prognosis are lacking. We retrospectively evaluated 72 pancreatic adenocarcinoma tumor resection patients at the University of Kansas Hospital between August 2009 and March 2019. Patients were divided into one of two groups, PanIN or IPMN, based on the results of the surgical pathology report. We compared baseline characteristics, overall survival (OS), and progression free survival (PFS) between the two groups, as well as OS and PFS based on local or distant tumor recurrence for both groups combined. 52 patients had PanINs and 20 patients had IPMNs. Patients who had an IPMN precursor lesion had better median PFS and OS when compared to patients with PanIN precursor lesions. However, the location of tumor recurrence (local or distant) did not show a statistically significant difference in OS.

Suppressing STAT5 signaling affects osteosarcoma growth and stemness.

Osteosarcoma (OS) is the most common primary bone tumor that primarily affects children and adolescents. Studies suggested that dysregulation JAK/STAT signaling promotes the development of OS. Cells treated with pimozide, a STAT5 inhibitor suppressed proliferation and colony formation and induced sub G0/G1 cell cycle arrest and apoptosis. There was a reduction in cyclin D1 and CDK2 expression and Rb phosphorylation, and activation of Caspase-3 and PARP cleavage. In addition, pimozide suppressed the formation of 3-dimensional osteospheres and growth of the cells in the Tumor in a Dish lung organoid system. Furthermore, there was a reduction in expression of cancer stem cell marker proteins DCLK1, CD44, CD133, Oct-4, and ABCG2. More importantly, it was the short form of DCLK1 that was upregulated in osteospheres, which was suppressed in response to pimozide. We further confirmed by flow cytometry a reduction in DCLK1+ cells. Moreover, pimozide inhibits the phosphorylation of STAT5, STAT3, and ERK in OS cells. Molecular docking studies suggest that pimozide interacts with STAT5A and STAT5B with binding energies of -8.4 and -6.4 Kcal/mol, respectively. Binding was confirmed by cellular thermal shift assay. To further understand the role of STAT5, we knocked down the two isoforms using specific siRNAs. While knockdown of the proteins did not affect the cells, knockdown of STAT5B reduced pimozide-induced necrosis and further enhanced late apoptosis. To determine the effect of pimozide on tumor growth in vivo, we administered pimozide intraperitoneally at a dose of 10 mg/kg BW every day for 21 days in mice carrying KHOS/NP tumor xenografts. Pimozide treatment significantly suppressed xenograft growth. Western blot and immunohistochemistry analyses also demonstrated significant inhibition of stem cell marker proteins. Together, these data suggest that pimozide treatment suppresses OS growth by targeting both proliferating cells and stem cells at least in part by inhibiting the STAT5 signaling pathway.

Cucurbitacin B and I inhibits colon cancer growth by targeting the Notch signaling pathway.

Cancer stem cells (CSCs) have the ability to self-renew and induce drug resistance and recurrence in colorectal cancer (CRC). As current chemotherapy doesn't eliminate CSCs completely, there is a need to identify novel agents to target them. We investigated the effects of cucurbitacin B (C-B) or I (C-I), a natural compound that exists in edible plants (bitter melons, cucumbers, pumpkins and zucchini), against CRC. C-B or C-I inhibited proliferation, clonogenicity, induced G2/M cell-cycle arrest and caspase-mediated-apoptosis of CRC cells. C-B or C-I suppressed colonosphere formation and inhibited expression of CD44, DCLK1 and LGR5. These compounds inhibited notch signaling by reducing the expression of Notch 1-4 receptors, their ligands (Jagged 1-2, DLL1,3,4), γ-secretase complex proteins (Presenilin 1, Nicastrin), and downstream target Hes-1. Molecular docking showed that C-B or C-I binds to the ankyrin domain of Notch receptor, which was confirmed using the cellular thermal shift assay. Finally, C-B or C-I inhibited tumor xenograft growth in nude mice and decreased the expression of CSC-markers and notch signaling proteins in tumor tissues. Together, our study suggests that C-B and C-I inhibit colon cancer growth by inhibiting Notch signaling pathway.