Phase II study of nivolumab in patients with genetic alterations in DNA damage repair and response who progressed after standard treatment for metastatic solid cancers (KM-06).

BACKGROUND: Immune-modulating antibodies targeting programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) have demonstrated promising antitumor efficacy in various types of cancers, especially highly mutated ones. Genetic alterations in DNA damage response and repair (DDR) genes can lead to genetic instability, often accompanied by a high tumor mutation burden (TMB). However, few studies have validated the aberration of DDR genes as a predictive biomarker for response to immune-modulating antibodies. METHODS: The KM-06 open-label, multicenter, single-arm, phase II trial evaluated the safety and efficacy of nivolumab in refractory solid cancers with DDR gene mutations assessed by clinically targeted sequencing. Nivolumab (3 mg/kg) was administered every 2 weeks until disease progression, unacceptable toxicity, or for 24 months. The primary endpoint was the objective response rate (ORR) as per RECIST V.1.1 criteria. RESULTS: A total of 48 patients were enrolled in the study (median age 61, 58.3% male). The most common cancer type was colorectal cancer (41.7%), followed by prostate and biliary tract cancer (8.3% each). Eight patients achieved a partial response as their best overall response, resulting in an ORR of 17.8%. The disease control rate was 60.0%. The median progression-free survival was 2.9 months. Treatment-related adverse events of any grade and grade ≥3 occurred in 44 (91.7%) and 4 (8.3%) patients, respectively. Clinically targeted sequencing data inferred both TMB and microsatellite instability (MSI). Using a TMB cut-off of 12 mut/Mb, there were significant differences in overall survival (p=0.00035), progression-free survival (p=0.0061), and the best overall response (p=0.05). In the RNA sequencing analysis, nivolumab responders showed activation of the interleukin signaling pathway. Patients who experienced early progression presented high epithelial-mesenchymal transition signaling pathway activation. The responders exhibited a marked increase in PD-1-/Ki67+CD8 T cells at the early stage of treatment (C3D1) compared with non-responders (p=0.03). CONCLUSIONS: In this phase II trial, nivolumab demonstrated moderate efficacy and manageable toxicity in patients with solid cancer harboring DDR gene mutations. A high TMB (>12 mut/Mb) and MSI score (>2.5) determined through clinically target sequencing presented significant discriminatory power for the nivolumab response. TRIAL REGISTRATION NUMBER: NCT04761744.

Method to Determine the Optimal Aptamer-to-Bead Ratio by Using Flow Cytometry.

Research on the effective attachment of aptamers to beads, which is essential for using aptamers, has made relatively little progress. Here, we demonstrate a new method based on flow cytometry to determine the optimal aptamer-to-bead ratio for aptamer immobilization. The fluorescence intensity increased with a gradual two-fold increase in the aptamer fluorescence concentration, peaked at an aptamer-to-bead ratio of 2.56 × 105, and tended to decrease at higher ratios. A similar pattern was observed in an additional analysis using fluorescence microscopy. However, measurement of the free aptamer concentration after the aptamer-bead conjugation reaction revealed a large aptamer loss compared to the 1.28 × 105 aptamer-bead ratio. In addition, the binding efficiency of the aptamer/bead to the target was highest at the aptamer-to-bead ratio of 1.28 × 105. Taken together, our data suggest that the proposed method is the best and easiest for determining the optimal aptamer-to-bead ratio.

SP-1154, a novel synthetic TGF-ß inhibitor, alleviates obesity and hepatic steatosis in high-fat diet-induced mice.

OBJECTIVE: Obesity-induced inflamed visceral adipose tissue (VAT) secretes pro-inflammatory cytokines thereby promoting systemic inflammation and insulin resistance which further exacerbate obesity-associated nonalcoholic fatty liver disease (NAFLD). Transforming growth factor (TGF)-ß /Smad3 signaling plays a crucial role in the inflammatory events within the VAT. Here, we investigate whether SP-1154, a novel synthetic verbenone derivative, can inhibit TGF-ß/Smad3 signaling thereby exhibiting a therapeutic effect against obesity-induced inflamed VAT and subsequent NAFLD in high-fat diet-induced mice. METHODS: NAFLD was induced by a high-fat diet (60% fat) for 20 weeks using the male C57BL/6 mice. SP-1154 (50 mg/kg) was orally given daily for 20 weeks. In vivo VAT- and systemic inflammation were measured by using 18F-fluorodeoxyglucose positron emission tomography and C-reactive protein levels. Both insulin tolerance- and glucose tolerance test were performed to assess the status of insulin resistance and glucose intolerance. Histological and molecular analyses were performed on harvested liver and VAT. KEY FINDINGS: SP-1154 inhibited TGF-ß/Smad3 signaling pathway and remarkably suppressed high-fat diet-induced VAT inflammation and its related systemic inflammation. Furthermore, SP-1154 significantly improved insulin sensitivity with glucose homeostasis and reduced hepatic steatosis. SP-1154 significantly improves VAT inflammation and obesity-related NAFLD. CONCLUSION: Our novel findings support the potential use of SP-1154 as a therapeutic drug for obesity and its related NAFLD by targeting the inflamed VAT.

Cystine and Methionine Deficiency Promotes Ferroptosis by Inducing B-Cell Translocation Gene 1.

Ferroptosis is a type of programmed necrosis triggered by iron-dependent lipid peroxidation. We investigated the role of B-cell translocation gene 1 (BTG1) in cystine and methionine deficiency (CST/Met (-))-mediated cell death. CST/Met (-) depleted reduced and oxidized glutathione in hepatocyte-derived cells, increased prostaglandin-endoperoxide synthase 2 expression, and promoted reactive oxygen species accumulation and lipid peroxidation, as well as necrotic cell death. CST/Met (-)-mediated cell death and lipid peroxidation was specifically inhibited by pretreatment with ferroptosis inhibitors. In parallel with cell death, CST/Met (-) blocked global protein translation and increased the expression of genes associated with the integrated stress response. Moreover, CST/Met (-) significantly induced BTG1 expression. Using a BTG1 promoter-harboring reporter gene and siRNA, activating transcription factor 4 (ATF4) was identified as an essential transcription factor for CST/Met (-)-mediated BTG1 induction. Although knockout of BTG1 in human HAP1 cells did not affect the accumulation of reactive oxygen species induced by CST/Met (-), BTG1 knockout significantly decreased the induction of genes associated with the integrated stress response, and reduced lipid peroxidation and cell death in response to CST/Met (-). The results demonstrate that CST/Met (-) induces ferroptosis by activating ATF4-dependent BTG1 induction.

Integrated targeted serum metabolomic profile and its association with gender, age, disease severity, and pattern identification in acne.

BACKGROUND: Westernized diet and nutritional metabolism are important in acne pathogenesis, especially in adult patients. However, clinical and basic data are lacking. Pattern identification (PI) is a tool that results in a diagnostic conclusion based on a cluster of concurrent symptoms and signs in traditional medicine. Acne can be classified by PI. However, whether the metabolomic profile differs according to the PI of acne is unknown. Metabolomic data would help clarify the pathogenesis of acne. METHODS: We conducted a cross-sectional study involving 40 healthy controls and 60 subjects with acne. We evaluated androgens, serum lipids, essential amino acids, nonessential amino acids, other amino acids, and pro-inflammatory cytokines of all subjects and compared the metabolomic profiles between acne subjects and healthy controls, and in subgroups according to gender, age, severity, and PI. RESULTS: Dehydroepiandrosterone sulfate and serum fatty acids were significantly higher in female subjects, adolescents, and those with disharmony of the thoroughfare and conception vessels. The total essential and nonessential amino acids were significantly lower in the overall, female, adult, severe, and phlegm-stasis group. The latter group exhibited elevated serum levels of interleukin-1ß and -6. CONCLUSIONS: This is the first study to investigate serum lipids, amino acids, and cytokines in subjects with acne. We analyzed the differences between metabolomic profiles to determine the diagnostic value of PI. Prospective studies with more patients are needed to confirm the characteristics of each PI and lipidomic data will enrich knowledge concerning lipid mechanism.

CCR4­NOT transcription complex subunit 2 regulates TRAIL sensitivity in non­small­cell lung cancer cells via the STAT3 pathway.

TRAIL is an attractive candidate for anticancer therapy in a variety of tumors since it targets only tumors and not normal tissue. However, a remaining major hurdle is that the majority of tumors exhibit a resistance mechanism against the effects of TRAIL via the induction of anti­apoptotic signaling pathways. In this study, we aimed to evaluate whether the modulation of CCR4­NOT transcription complex subunit 2 (CNOT2) function can promote TRAIL sensitivity in non­small­cell lung cancer (NSCLC) cells. CNOT2 depletion partially decreased colony numbers and the proliferation of NSCLC cells. When combined with TRAIL, the suppression of CNOT2 expression markedly decreased the survival rate and increased apoptosis, as compared with TRAIL treatment alone in TRAIL­resistant NSCLC cells. Of note, CNOT2 overexpression in TRAIL­sensitive H460 cells enhanced the survival rate and decreased apoptosis when compared with TRAIL treatment alone. Gene expression analysis indicated that genes involved in the signal transducer and activator of transcription 3 (STAT3) signaling pathway were dominantly altered in the CNOT2­depleted A549 cells. Under this condition, Src homology region 2 domain containing phosphatase­1 (SHP1) was significantly upregulated and subsequently increased apoptosis. On the whole, the findings of this study demonstrate that CNOT2 participates in TRAIL sensitivity in NSCLC cells via the regulation of the STAT3 signaling pathway, and suggest that combination therapy with CNOT2 depletion and TRAIL treatment may prove to be a useful strategy for overcoming TRAIL resistance in NSCLC.

Correction: The heparan sulfate mimetic PG545 interferes with Wnt/ß-catenin signaling and significantly suppresses pancreatic tumorigenesis alone and in combination with gemcitabine.

[This corrects the article DOI: 10.18632/oncotarget.3214.].

Papaver nudicaule (Iceland poppy) alleviates lipopolysaccharide-induced inflammation through inactivating NF-κB and STAT3.

BACKGROUND: Papaver nudicaule belongs to the Papaveraceae family, which is planted as an annual herbaceous species generally for ornamental purpose. Papaver rhoeas in the same family has been reported to have various pharmacological activities such as antioxidant and analgesic effects. In contrast, little is known about the pharmacological activity of Papaver nudicaule. In this study, the anti-inflammatory activity of Papaver nudicaule extracts and the action mechanisms were investigated in RAW264.7 macrophage cells. METHODS: To investigate the anti-inflammatory activity of five cultivars of Papaver nudicaule with different flower color, samples were collected from their aerial parts at two growth stages (60 and 90 days) and their ethanol extracts were evaluated in the lipopolysaccharide (LPS)-treated RAW264.7 cells by measuring nitric oxide (NO) and prostaglandin E2 (PGE2) levels. Interleukin 1-beta (IL-1ß), Interleukin-6 (IL-6) and Tumor necrosis factor alpha (TNF-α) production were also analyzed by RT-PCR and multiplex assays. Nuclear Factor-kappa-light-chain-enhancer of activated B cells (NF-κB) and Signal transducer and activator of transcription 3 (STAT3) signaling pathways were examined using western blotting and luciferase reporter assays to reveal the action mechanism of Papaver nudicaule extracts in their anti-inflammatory activity. RESULTS: All of the Papaver nudicaule extracts were effective in reducing the LPS-induced NO, which is an important inflammatory mediator, and the extract of Papaver nudicaule with white flower collected at 90 days (NW90) was selected for further experiments because of the best effect on reducing the LPS-induced NO as well as no toxicity. NW90 lowered the LPS-induced PGE2 level and decreased the LPS-induced Nitric oxide synthase 2 (NOS2) and Cyclooxygenase 2 (COX2). In addition, NW90 reduced the LPS-induced inflammatory cytokines, IL-1ß and IL-6. Furthermore, NW90 inhibited the LPS-induced activation of NF-κB and STAT3. CONCLUSIONS: These results indicate that NW90 may restrain inflammation by inhibiting NF-κB and STAT3, suggesting the potential therapeutic properties of Papaver nudicaule against inflammatory disease.

Casticin inhibits growth and enhances ionizing radiation-induced apoptosis through the suppression of STAT3 signaling cascade.

Casticin (CTC), one of the major components of Vitex rotundifolia L., has been reported to exert significant beneficial pharmacological activities and can function as an antiprolactin, anticancer, anti-inflammatory, neuroprotective, analgesic, and immunomodulatory agent. This study aimed at investigating whether the proapoptotic effects of CTC may be mediated through the abrogation of signal transducers and activators of transcription-3 (STAT3) signaling pathway in a variety of human tumor cells. We found that CTC significantly decreased cell viability in a concentration-dependent manner and suppressed cell proliferation in 786-O, YD-8, and HN-9 cells. CTC also induced programmed cell death that was found to be mediated via caspase-3 activation and induction of poly(ADP-ribose) polymerase cleavage. Interestingly, CTC repressed both constitutive and interleukin-6-induced STAT3 activation in 786-O and YD-8 cells but only affected constitutive STAT3 phosphorylation in HN-9 cells. Moreover, CTC could potentiate ionizing radiation-induced apoptotic effects leading to the downregulation of STAT3 activation and thus may be used in combination with radiation against diverse malignancies.

Retraction Note: Umbilical cord tissue-derived mesenchymal stem cells induce apoptosis in PC-3 prostate cancer cells through activation of JNK and downregulation of PI3K/AKT signaling.

This article [1] has been retracted by the authors because, contrary to the statement in the article, ethical approval was not obtained to conduct this study.

Identification and metabolite profiling of alkaloids in aerial parts of Papaver rhoeas by liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.

Papaver plants can produce diverse bioactive alkaloids. Papaver rhoeas Linnaeus (common poppy or corn poppy) is an annual flowering medicinal plant used for treating cough, sleep disorder, and as a sedative, pain reliever, and food. It contains various powerful alkaloids like rhoeadine, benzylisoquinoline, and proaporphine. To investigate and identify alkaloids in the aerial parts of P. rhoeas, samples were collected at different growth stages and analyzed using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. A liquid chromatography with mass spectrometry method was developed for the identification and metabolite profiling of alkaloids for P. rhoeas by comparing with Papaver somniferum. Eighteen alkaloids involved in benzylisoquinoline alkaloid biosynthesis were used to optimize the liquid chromatography gradient and mass spectrometry conditions. Fifty-five alkaloids, including protoberberine, benzylisoquinoline, aporphine, benzophenanthridine, and rhoeadine-type alkaloids, were identified authentically or tentatively by liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry in samples taken during various growth stages. Rhoeadine alkaloids were observed only in P. rhoeas samples, and codeine and morphine were tentatively identified in P. somniferum. The liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry method can be a powerful tool for the identification of diverse metabolites in the genus Papaver. These results may help understand the biosynthesis of alkaloids in P. rhoeas and evaluate the quality of this plant for possible medicinal applications.

Corrigendum to "Apoptosis Induced by Tanshinone IIA and Cryptotanshinone Is Mediated by Distinct JAK/STAT3/5 and SHP1/2 Signaling in Chronic Myeloid Leukemia K562 Cells".

[This corrects the article DOI: 10.1155/2013/805639.].

A comparative study of biological and metabolic biomarkers between healthy individuals and patients with acne vulgaris: A cross-sectional study protocol.

Acne is a multifactorial dermatosis, which is influenced not only by hormones but also by the biochemical relationship between them and the pilosebaceous unit. Inflammatory cytokines, chemokines, active oxygen, and zinc are known to be associated with the development of acne. Further, steroid metabolism is known as one of the important factors related to sebum secretion and comedone formation in acne. However, there is a lack of studies comparing these human biomarkers between healthy individuals and patients with acne. In particular, no study has investigated the relationship between human biomarkers and patterns of acne yet.The purpose of this study is to investigate diagnostic human biomarkers in acne by comparing the biological and metabolic biomarkers between healthy individuals and patients with acne and identify the relationship between human biomarkers and patterns of acne.This study is a protocol for a cross-sectional study. Forty healthy participants and 60 patients with acne will be recruited at 1 center. We will collect their blood samples and analyze the molecular biological and metabolic biomarkers (cytokines, chemokines, reactive oxygen species, corticotropin-releasing hormone, zinc, amino acid, 1-carbon metabolite, lipid metabolite, etc.). Further, we will administer questionnaires regarding their diet, sleep, stress, and other factors relating to acne and measure their skin elasticity.The study protocol was approved by the Institutional Review Board of Oriental Medical Hospital at Kyung Hee Medical Center (KOMCIRB-161118-HR-062). Written informed consent will be obtained from all the participants. The trial was registered in the Clinical Research Information Service, Republic of Korea: KCT0002212.This trial will provide evidence regarding diagnostic human biomarkers in acne and the relationship between the human biomarkers and patterns of acne.

Morusin induces apoptosis by regulating expression of Bax and Survivin in human breast cancer cells.

Morusin which has been isolated from the root bark of Morus alba L. (Moraceae) has previously demonstrated anticancer activity in various types of cancer cells such as hepatocellular carcinoma, glioma and prostate cancer. However, the effect of morusin on breast cancer cells remains unclear. In the present study, the potential of morusin as an anti-cancer agent in breast cancer was investigated. The results of the present study revealed that the treatment of morusin induced cell death in various human breast cancer cell lines, but exhibited little effect on normal human breast epithelial cells. In Annexin V-propidium iodide double staining assays, morusin significantly increased apoptosis in a dose-dependent manner in human breast cancer cells. The apoptosis marker proteins cleaved caspase 3 and 9 were consistently upregulated following treatment of cells with morusin in a time- and dose-dependent manner. Furthermore, morusin was demonstrated to modulate the expression of the anti-apoptotic protein Survivin and pro-apoptotic protein B-cell lymphoma 2-associated-x protein (Bax) in human breast cancer cells. These results indicate that morusin induces apoptosis by suppressing Survivin and inducing Bax proteins, suggesting that morusin is a potentially effective therapeutic agent for the treatment of patients with breast cancer.

Tanshinone IIA induces TRAIL sensitization of human lung cancer cells through selective ER stress induction.

Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promised anticancer medicine targeting only the tumor, most cancers show resistance to TRAIL-induced apoptosis. For this reason, new therapeutic strategies to overcome the TRAIL resistance are required for more effective tumor treatment. In the present study, potential of tanshinone IIA as a TRAIL sensitizer was evaluated in human non-small cell lung cancer (NSCLC) cells. NSCLC cells showed resistance to TRAIL-mediated cell death, but combination treatment of Tanshinone IIA and TRAIL synergistically decreased cell viability and increased apoptosis in TRAIL-resistant NSCLC cells. Tanshinone IIA greatly induced death receptor 5 (DR5), but not death receptor 4 (DR4). Furthermore, DR5 knockdown attenuated the combination treatment of tanshinone IIA with TRAIL-mediated cell death in human NSCLC cells. Tanshinone IIA also increased CHOP and activated the PERK-ATF4 pathway suggesting that tanshinone IIA increased DR5 and CHOP by activating the PERK-ATF4 pathway. Tanshinone IIA also downregulated phosphorylation of STAT3 and expression of survivin. Taken together, these results indicate that tanshinone IIA increases TRAIL-induced cell death via upregulating DR5 and downregulating survivin mediated by, respectively, selective activation of PERK/ATF4 and inhibition of STAT3, suggesting combinatorial intervention of tanshinone IIA and TRAIL as a new therapeutic strategy for human NSCLC.

Decursin enhances TRAIL-induced apoptosis through oxidative stress mediated- endoplasmic reticulum stress signalling in non-small cell lung cancers.

BACKGROUND AND PURPOSE: The TNF-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent due to its remarkable ability to selectively kill tumour cells. However, because most tumours exhibit resistance to TRAIL-induced apoptosis, the development of combination therapies to overcome resistance to TRAIL is required for effective cancer therapy. EXPERIMENTAL APPROACH: Cell viability and possible synergy between the plant pyranocoumarin decursin and TRAIL was measured by MTT assay and calcusyn software. Reactive oxygen species (ROS) and apoptosis were measured using dichlorodihydrofluorescein and annexin/propidium iodide in cell flow cytometry. Changes in protein levels were assessed with Western blotting. KEY RESULTS: Combining decursin and TRAIL markedly decreased cell viability and increased apoptosis in TRAIL-resistant non-small-cell lung cancer (NSCLC) cell lines. Decursin induced expression of the death receptor 5 (DR5). Inhibition of DR5 attenuated apoptotic cell death in decursin + TRAIL treated NSCLC cell lines. Interestingly, induction of DR5 and CCAAT/enhancer-binding protein homologues protein by decursin was mediated through selective induction of the pancreatic endoplasmic reticulum kinase (PERK)/activating transcription factor 4 (ATF4) branch of the endoplasmic reticulum stress response pathway. Furthermore, enhancement of PERK/ATF4 signalling by decursin was mediated by ROS generation in NSCLC cell lines, but not in normal human lung cells. Decursin also markedly down-regulated expression of survivin and Bcl-xL in TRAIL-resistant NSCLC cells. CONCLUSIONS AND IMPLICATIONS: ROS generation by decursin selectively activated the PERK/ATF4 axis of the endoplasmic reticulum stress signalling pathway, leading to enhanced TRAIL sensitivity in TRAIL-resistant NSCLC cell lines, partly via up-regulation of DR5.

Cinnamaldehyde derivative (CB-PIC) sensitizes chemo-resistant cancer cells to drug-induced apoptosis via suppression of MDR1 and its upstream STAT3 and AKT signalling.

BACKGROUND/AIMS: Our group reported that cinnamaldehyde derivative, (E)-4-((2-(3-oxopop-1-enyl)phenoxy)methyl)pyridinium malonic acid (CB-PIC) induced apoptosis in hypoxic SW620 colorectal cancer cells via activation of AMP-activated protein kinase (AMPK) and extracellular signal regulated kinase (ERK). Herein, sensitizing effect of CB-PIC was investigated in resistant cancer cells such as paclitaxel (PT) resistant lung cancer cells (H460/PT), and Adriamycin (Adr) resistant breast cancer (MCF7/Adr) and colon cancer (HCT15/cos) cells. METHODS: Various drug resistant cell lines were treated with CB-PIC, and the signalling pathway and functional assay were explored by Western blot, Rhodamine assay, FACS, RT-PCR and MTT assay. RESULTS: We found that CB-PIC effectively exerted cytotoxicity, increased sub G1 population and the cleaved form of poly (ADP-ribose) polymerase (PARP) and caspase 9 in drug resistant cancer cells. Furthermore, CB-PIC sensitized resistant cancer cells to adriamycin via downregulation of survival proteins such as survivin, Bcl-xL and Bcl-2, along with MDR1 suppression leading to accumulation of drug in the intracellular region. Of note, CB-PIC transcriptionally decreased MDR1 expression via suppression of STAT3 and AKT signalling in three resistant cancer cells with highly expressed P-glycoprotein. Nonetheless, CB-PIC did not affect transport activity of P-glycoprotein in a short time efflux assay, while epigallocatechin gallate (EGCG) accumulated Rhodamine 123 into intracellular region of cell by direct inhibition of MDR1 transport activity. CONCLUSIONS: These data demonstrate that CB-PIC suppresses the P-glycoprotein expression through inhibition of STAT3 and AKT signalling to overcome drug resistance in chemo-resistant cancer cells as a potent chemotherapeutic sensitizer.

A derivative of epigallocatechin-3-gallate induces apoptosis via SHP-1-mediated suppression of BCR-ABL and STAT3 signalling in chronic myelogenous leukaemia.

BACKGROUND AND PURPOSE: Epigallocatechin-3-gallate (EGCG) is a component of green tea known to have chemo-preventative effects on several cancers. However, EGCG has limited clinical application, which necessitates the development of a more effective EGCG prodrug as an anticancer agent. EXPERIMENTAL APPROACH: Derivatives of EGCG were evaluated for their stability and anti-tumour activity in human chronic myeloid leukaemia (CML) K562 and KBM5 cells. KEY RESULTS: EGCG-mono-palmitate (EGCG-MP) showed most prolonged stability compared with other EGCG derivatives. EGCG-MP exerted greater cytotoxicity and apoptosis in K562 and KBM5 cells than the other EGCG derivatives. EGCG-MP induced Src-homology 2 domain-containing tyrosine phosphatase 1 (SHP-1) leading decreased oncogenic protein BCR-ABL and STAT3 phosphorylation in CML cells, compared with treatment with EGCG. Furthermore, EGCG-MP reduced phosphorylation of STAT3 and survival genes in K562 cells, compared with EGCG. Conversely, depletion of SHP-1 or application of the tyrosine phosphatase inhibitor pervanadate blocked the ability of EGCG-MP to suppress phosphorylation of BCR-ABL and STAT3, and the expression of survival genes downstream of STAT3. In addition, EGCG-MP treatment more effectively suppressed tumour growth in BALB/c athymic nude mice compared with untreated controls or EGCG treatment. Immunohistochemistry revealed increased caspase 3 and SHP-1 activity and decreased phosphorylation of BCR-ABL in the EGCG-MP-treated group relative to that in the EGCG-treated group. CONCLUSIONS AND IMPLICATIONS: EGCG-MP induced SHP-1-mediated inhibition of BCR-ABL and STAT3 signalling in vitro and in vivo more effectively than EGCG. This derivative may be a potent chemotherapeutic agent for CML treatment.

The heparan sulfate mimetic PG545 interferes with Wnt/ß-catenin signaling and significantly suppresses pancreatic tumorigenesis alone and in combination with gemcitabine.

The heparan sulfate mimetic PG545 has been shown to exert anti-angiogenic and anti-metastatic activity in vitro and in vivo cancer models. Although much of this activity has been attributed to inhibition of heparanase and heparan sulfate-binding growth factors, it was hypothesized that PG545 may additionally disrupt Wnt signaling, an important pathway underlying the malignancy of pancreatic cancer. We show that PG545, by directly interacting with Wnt3a and Wnt7a, inhibits Wnt/ß-catenin signaling leading to inhibition of proliferation in pancreatic tumor cell lines. Additionally, we demonstrate for the first time that the combination of PG545 with gemcitabine has strong synergistic effects on viability, motility and apoptosis induction in several pancreatic cell lines. In an orthotopic xenograft mouse model, combination of PG545 with gemcitabine efficiently inhibited tumor growth and metastasis compared to single treatment alone. Also, PG545 treatment alone decreased the levels of ß-catenin and its downstream targets, cyclin D1, MMP-7 and VEGF which is consistent with our in vitro data. Collectively, our findings suggest that PG545 exerts anti-tumor activity by disrupting Wnt/ß-catenin signaling and combination with gemcitabine should be considered as a novel therapeutic strategy for pancreatic cancer treatment.

Homotypic NK cell-to-cell communication controls cytokine responsiveness of innate immune NK cells.

While stationary organ cells are in continuous contact with neighboring cells, immune cells circulate throughout the body without an apparent requirement for cell-cell contact to persist in vivo. This study challenges current convention by demonstrating, both in vitro and in vivo, that innate immune NK cells can engage in homotypic NK-to-NK cell interactions for optimal survival, activation, and proliferation. Using a specialized cell-laden microwell approach, we discover that NK cells experiencing constant NK-to-NK contact exhibit a synergistic increase in activation status, cell proliferation, and anti-tumor function in response to IL-2 or IL-15. This effect is dependent on 2B4/CD48 ligation and an active cytoskeleton, resulting in amplification of IL-2 receptor signaling, enhanced CD122/CD132 colocalization, CD25 upregulation, and Stat3 activation. Conversely, 'orphan' NK cells demonstrate no such synergy and fail to persist. Therefore, our data uncover the existence of homotypic cell-to-cell communication among mobile innate lymphocytes, which promotes functional synergy within the cytokine-rich microenvironment.