Sulindac plus a phospholipid is effective for polyp reduction and safer than sulindac alone in a mouse model of colorectal cancer development.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and sulindac are effective for colorectal cancer prevention in humans and some animal models, but concerns over gastro-intestinal (GI) ulceration and bleeding limit their potential for chemopreventive use in broader populations. Recently, the combination of aspirin with a phospholipid, packaged as PL-ASA, was shown to reduce GI toxicity in a small clinical trial. However, these studies were done for relatively short periods of time. Since prolonged, regular use is needed for chemopreventive benefit, it is important to know whether GI safety is maintained over longer use periods and whether cancer prevention efficacy is preserved when an NSAID is combined with a phospholipid. METHODS: As a first step to answering these questions, we treated seven to eight-week-old, male and female C57B/6 Apcmin/+ mice with the NSAID sulindac, with and without phosphatidylcholine (PC) for 3-weeks. At the end of the treatment period, we evaluated polyp burden, gastric toxicity, urinary prostaglandins (as a marker of sulindac target engagement), and blood chemistries. RESULTS: Both sulindac and sulindac-PC treatments resulted in significantly reduced polyp burden, and decreased urinary prostaglandins, but sulindac-PC treatment also resulted in the reduction of gastric lesions compared to sulindac alone. CONCLUSIONS: Together these data provide pre-clinical support for combining NSAIDs with a phospholipid, such as phosphatidylcholine to reduce GI toxicity while maintaining chemopreventive efficacy.

EGF-induced ERK activation promotes CK2-mediated disassociation of alpha-Catenin from beta-Catenin and transactivation of beta-Catenin.

Increased transcriptional activity of beta-catenin resulting from Wnt/Wingless-dependent or -independent signaling has been detected in many types of human cancer, but the underlying mechanism of Wnt-independent regulation remains unclear. We demonstrate here that EGFR activation results in disruption of the complex of beta-catenin and alpha-catenin, thereby abrogating the inhibitory effect of alpha-catenin on beta-catenin transactivation via CK2alpha-dependent phosphorylation of alpha-catenin at S641. ERK2, which is activated by EGFR signaling, directly binds to CK2alpha via the ERK2 docking groove and phosphorylates CK2alpha primarily at T360/S362, subsequently enhancing CK2alpha activity toward alpha-catenin phosphorylation. In addition, levels of alpha-catenin S641 phosphorylation correlate with levels of ERK1/2 activity in human glioblastoma specimens and with grades of glioma malignancy. This EGFR-ERK-CK2-mediated phosphorylation of alpha-catenin promotes beta-catenin transactivation and tumor cell invasion. These findings highlight the importance of the crosstalk between EGFR and Wnt pathways in tumor development.

Siglec-G-CD24 axis controls the severity of graft-versus-host disease in mice.

Activation of sialic-acid-binding immunoglobulin-like lectin-G (Siglec-G) by noninfectious damage-associated molecular patterns controls innate immune responses. However, whether it also regulates T-cell-mediated adaptive immune responses is not known. Graft-versus-host reaction is a robust adaptive immune response caused by allogeneic hematopoietic cell transplantation that have been activated by antigen-presenting cells (APCs) in the context of damaged host tissues following allogeneic hematopoietic cell transplantation. The role of infectious and noninfectious pattern recognition receptor-mediated activation in the induction and aggravation of graft-versus-host disease (GVHD) is being increasingly appreciated. But the role of pathways that control innate immune responses to noninfectious stimuli in modulating GVHD has heretofore not been recognized. We report that Siglec-G expression on host APCs, specifically on hematopoietic cells, negatively regulates GVHD in multiple clinically relevant murine models. Mechanistic studies with various relevant Siglec-G and CD24 knockout mice and chimeric animals, along with rescue experiments with novel CD24 fusion protein demonstrate that enhancing the interaction between Siglec-G on host APCs with CD24 on donor T cells attenuates GVHD. Taken together, our data demonstrate that Siglec-G-CD24 axis, controls the severity of GVHD and suggest that enhancing this interaction may represent a novel strategy for mitigating GVHD.

Ex Vivo Expanded Cord Blood Natural Killer Cells Combined with Rituximab and High-Dose Chemotherapy and Autologous Stem Cell Transplantation for B Cell Non-Hodgkin Lymphoma.

Relapse is the major cause of failure of high-dose chemotherapy (HDC) with autologous stem cell transplantation (ASCT) for B cell non-Hodgkin lymphomas (B-NHL). Improvement strategies include use in combination with effective immunotherapies. We hypothesized that the combination of rituximab/HDC/ASCT with expanded cord blood (CB)-derived natural killer (NK) cells is safe and active in B-NHL. Patients with B-NHL age 15 to 70 years and appropriate ASCT candidates were eligible for the study. The CB units were selected without considering HLA match with the recipient. The CB NK cells were expanded from day -19 to day -5. Treatment included rituximab on days -13 and -7, BEAM (carmustine/etoposide/cytarabine/melphalan) on days -13 to -7, lenalidomide on days -7 to -2, CB NK infusion (108/kg) on day -5, and ASCT (day 0). The primary endpoint was 30-day treatment-related mortality (TRM); secondary endpoints included relapse-free survival (RFS), overall survival (OS), and persistence of CB NK cells. We enrolled 20 patients. CB NK cells were expanded a median of 1552-fold with >98% purity and >96% viability. We saw no adverse events attributable to the CB NK cells and 0% 30-day TRM. At median follow-up of 47 months, the RFS and OS rates were 53% and 74%, respectively. CB NK cells were detectable in blood for 2 weeks, independent of HLA-mismatch status. CD16 expression in donor NK cells was correlated favorably with outcome, and homozygosity for the high-affinity CD16 variant (158 V/V) in CB, but not recipient, NK cells was correlated with better outcomes. Our data indicate that the combination of expanded and highly purified CB-derived NK cells with HDC/ASCT for B-NHL is safe. CD16 expression in donor NK cells, particularly if homozygous for the high-affinity CD16 variant, was correlated with better outcomes.

Bcr-Abl ubiquitination and Usp9x inhibition block kinase signaling and promote CML cell apoptosis.

Although chronic myelogenous leukemia (CML) is effectively controlled by Bcr-Abl kinase inhibitors, resistance to inhibitors, progressive disease, and incomplete eradication of Bcr-Abl-expressing cells are concerns for the long-term control and suppression of this disease. We describe a novel approach to targeting key proteins in CML cells with a ubiquitin-cycle inhibitor, WP1130. Bcr-Abl is rapidly modified with K63-linked ubiquitin polymers in WP1130-treated CML cells, resulting in its accumulation in aggresomes, where is it unable to conduct signal transduction. Induction of apoptosis because of aggresomal compartmentalization of Bcr-Abl was observed in both imatinib-sensitive and -resistant cells. WP1130, but not Bcr-Abl kinase inhibitors, directly inhibits Usp9x deubiquitinase activity, resulting in the down-regulation of the prosurvival protein Mcl-1 and facilitating apoptosis. These results demonstrate that ubiquitin-cycle inhibition represents a novel and effective approach to blocking Bcr-Abl kinase signaling and reducing Mcl-1 levels to engage CML cell apoptosis. This approach may be a therapeutic option for kinase inhibitor-resistant CML patients.

A Case Study of Chimeric Antigen Receptor T Cell Function: Donor Therapeutic Differences in Activity and Modulation with Verteporfin.

BACKGROUND: Chimeric antigen receptor (CAR) T cells have recently been demonstrated to extract and express cognate tumor antigens through trogocytosis. This process may contribute to tumor antigen escape, T cell exhaustion, and fratricide, which plays a central role in CAR dysfunction. We sought to evaluate the importance of this effect in epidermal growth factor receptor variant III (EGFRvIII) specific CAR T cells targeting glioma. METHODS: EGFRvIII-specific CAR T cells were generated from various donors and analyzed for cytotoxicity, trogocytosis, and in vivo therapeutic activity against intracranial glioma. Tumor autophagy resulting from CAR T cell activity was evaluated in combination with an autophagy inducer (verteporfin) or inhibitor (bafilomycin A1). RESULTS: CAR T cell products derived from different donors induced markedly divergent levels of trogocytosis of tumor antigen as well as PD-L1 upon engaging target tumor cells correlating with variability in efficacy in mice. Pharmacological facilitation of CAR induced-autophagy with verteporfin inhibits trogocytic expression of tumor antigen on CARs and increases CAR persistence and efficacy in mice. CONCLUSION: These data propose CAR-induced autophagy as a mechanism counteracting CAR-induced trogocytosis and provide a new strategy to innovate high-performance CARs through pharmacological facilitation of T cell-induced tumor death.

Cell-directed aptamer therapeutic targeting for cancers including those within the central nervous system.

Osteopontin (OPN) is produced by tumor cells as well as by myeloid cells and is enriched in the tumor microenvironment (TME) of many cancers. Given the roles of OPN in tumor progression and immune suppression, we hypothesized that targeting OPN with aptamers that have high affinity and specificity could be a promising therapeutic strategy. Bi-specific aptamers targeting ligands for cellular internalization were conjugated to siRNAs to suppress OPN were created, and therapeutic leads were selected based on target engagement and in vivo activity. Aptamers as carriers for siRNA approaches were created including a cancer targeting nucleolin aptamer Ncl-OPN siRNA and a myeloid targeting CpG oligodeoxynucleotide (ODN)-OPN siRNA conjugate. These aptamers were selected as therapeutic leads based on 70-90% OPN inhibition in cancer (GL261, 344SQ, 4T1B2b) and myeloid (DC2.4) cells relative to scramble controls. In established immune competent 344SQ lung cancer and 4T1B2b breast cancer models, these aptamers, including in combination, demonstrate therapeutic activity by inhibiting tumor growth. The Ncl-OPN siRNA aptamer demonstrated efficacy in an immune competent orthotopic glioma model administered systemically secondary to the ability of the aptamer to access the glioma TME. Therapeutic activity was demonstrated using both aptamers in a breast cancer brain metastasis model. Targeted inhibition of OPN in tumor cells and myeloid cells using bifunctional aptamers that are internalized by specific cell types and suppress OPN expression once internalized may have clinical potential in cancer treatment.

A first-in-human Phase I trial of the oral p-STAT3 inhibitor WP1066 in patients with recurrent malignant glioma.

Aim: To ascertain the maximum tolerated dose (MTD)/maximum feasible dose (MFD) of WP1066 and p-STAT3 target engagement within recurrent glioblastoma (GBM) patients. Patients & methods: In a first-in-human open-label, single-center, single-arm 3 + 3 design Phase I clinical trial, eight patients were treated with WP1066 until disease progression or unacceptable toxicities. Results: In the absence of significant toxicity, the MFD was identified to be 8 mg/kg. The most common adverse event was grade 1 nausea and diarrhea in 50% of patients. No treatment-related deaths occurred; 6 of 8 patients died from disease progression and one was lost to follow-up. Of 8 patients with radiographic follow-up, all had progressive disease. The longest response duration exceeded 3.25 months. The median progression-free survival (PFS) time was 2.3 months (95% CI: 1.7 months-NA months), and 6-month PFS (PFS6) rate was 0%. The median overall survival (OS) rate was 25 months (95% CI: 22.5 months-NA months), with an estimated 1-year OS rate of 100%. Pharmacokinetic (PK) data demonstrated that at 8 mg/kg, the T1/2 was 2-3 h with a dose dependent increase in the Cmax. Immune monitoring of the peripheral blood demonstrated that there was p-STAT3 suppression starting at a dose of 1 mg/kg. Conclusion: Immune analyses indicated that WP1066 inhibited systemic immune p-STAT3. WP1066 had an MFD identified at 8 mg/kg which is the target allometric dose based on prior preclinical modeling in combination with radiation therapy and a Phase II study is being planned for newly diagnosed MGMT promoter unmethylated glioblastoma patients.

Homozygous deletion of glycogen synthase kinase 3beta bypasses senescence allowing Ras transformation of primary murine fibroblasts.

In primary mammalian cells, expression of oncogenes such as activated Ras induces premature senescence rather than transformation. We show that homozygous deletion of glycogen synthase kinase (GSK) 3beta (GSK3beta-/-) bypasses senescence induced by mutant Ras(V12) allowing primary mouse embryo fibroblasts (MEFs) as well as immortalized MEFs to exhibit a transformed phenotype in vitro and in vivo. Both catalytic activity and Axin-binding of GSK3beta are required to optimally suppress Ras transformation. The expression of Ras(V12) in GSK3beta-/-, but not in GSK3beta+/+ MEFs results in translocation of beta-catenin to the nucleus with concomitant up-regulation of cyclin D1. siRNA-mediated knockdown of beta-catenin decreases both cyclin D1 expression and anchorage-independent growth of transformed cells indicating a causal role for beta-catenin. Thus Ras(V12) and the lack of GSK3beta act in concert to activate the beta-catenin pathway, which may underlie the bypass of senescence and tumorigenic transformation by Ras.

The Role and Therapeutic Targeting of JAK/STAT Signaling in Glioblastoma.

Glioblastoma remains one of the deadliest and treatment-refractory human malignancies in large part due to its diffusely infiltrative nature, molecular heterogeneity, and capacity for immune escape. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway contributes substantively to a wide variety of protumorigenic functions, including proliferation, anti-apoptosis, angiogenesis, stem cell maintenance, and immune suppression. We review the current state of knowledge regarding the biological role of JAK/STAT signaling in glioblastoma, therapeutic strategies, and future directions for the field.

Intratumoral Delivery of STING Agonist Results in Clinical Responses in Canine Glioblastoma.

PURPOSE: Activation of STING (stimulator of interferon genes) can trigger a robust, innate antitumor immune response in immunologically "cold" tumors such as glioblastoma. PATIENTS AND METHODS: A small-molecule STING agonist, IACS-8779, was stereotactically administered using intraoperative navigation intratumorally in dogs with spontaneously arising glioblastoma. The phase I trial used an escalating dose design, ascending through four dose levels (5-20 µg). Treatment was repeated every 4-6 weeks for a minimum of two cycles. Radiographic response to treatment was determined by response assessment in neuro-oncology (RANO) criteria applied to isovoxel postcontrast T1-weighted MR images obtained on a single 3T magnet. RESULTS: Six dogs were enrolled and completed ≥1 cycle of treatment. One dog was determined to have an abscess and was removed from further analysis. One procedure-related fatality was observed. Radiographic responses were dose dependent after the first cycle. The first subject had progressive disease, whereas there was 25% volumetric reduction in one subject and greater than 50% in the remaining surviving subjects. The median progression-free survival time was 14 weeks (range: 0-22 weeks), and the median overall survival time was 32 weeks (range: 11-39 weeks). CONCLUSIONS: Intratumoral STING agonist (IACS-8779) administration was well tolerated in dogs with glioblastoma to a dose of 15 µg. Higher doses of IACS-8779 were associated with radiographic responses.

Opening of the Blood-Brain Barrier Using Low-Intensity Pulsed Ultrasound Enhances Responses to Immunotherapy in Preclinical Glioma Models.

PURPOSE: The blood-brain barrier (BBB) inhibits adequate dosing/penetration of therapeutic agents to malignancies in the brain. Low-intensity pulsed ultrasound (LIPU) is a safe therapeutic method of temporary BBB disruption (BBBD) to enhance chemotherapeutic delivery to the tumor and surrounding brain parenchyma for treatment of glioblastoma. EXPERIMENTAL DESIGN: We investigated if LIPU could enhance therapeutic efficacy of anti-PD-1 in C57BL/6 mice bearing intracranial GL261 gliomas, epidermal growth factor receptor variant III (EGFRvIII) chimeric antigen receptor (CAR) T cells in NSG mice with EGFRvIII-U87 gliomas, and a genetically engineered antigen-presenting cell (APC)-based therapy producing the T-cell attracting chemokine CXCL10 in the GL261-bearing mice. RESULTS: Mice treated with anti-PD-1 and LIPU-induced BBBD had a median survival duration of 58 days compared with 39 days for mice treated with anti-PD-1, and long-term survivors all remained alive after contralateral hemisphere rechallenge. CAR T-cell administration with LIPU-induced BBBD resulted in significant increases in CAR T-cell delivery to the CNS after 24 (P < 0.005) and 72 (P < 0.001) hours and increased median survival by greater than 129%, in comparison with CAR T cells alone. Local deposition of CXCL10-secreting APCs in the glioma microenvironment with LIPU enhanced T-cell glioma infiltration during the therapeutic window (P = 0.004) and markedly enhanced survival (P < 0.05). CONCLUSIONS: LIPU increases immune therapeutic delivery to the tumor microenvironment with an associated increase in survival and is an emerging technique for enhancing novel therapies in the brain.

MiR-181 Family Modulates Osteopontin in Glioblastoma Multiforme.

MiRNAs can silence a wide range of genes, which may be an advantage for targeting heterogenous tumors like glioblastoma. Osteopontin (OPN) plays both an oncogenic role in a variety of cancers and can immune modulate macrophages. We conducted a genome wide profiling and bioinformatic analysis to identify miR-181a/b/c/d as potential miRNAs that target OPN. Luciferase assays confirmed the binding potential of miRNAs to OPN. Expression levels of miR-181a/b/c/d and OPN were evaluated by using quantitative real-time PCR and enzyme-linked immunosorbent assay in mouse and human glioblastomas and macrophages that showed these miRNAs were downregulated in Glioblastoma associated CD11b+ cells compared to their matched blood CD14b+ cells. miRNA mimicking and overexpression using lentiviruses showed that MiR-181a overexpression in glioblastoma cells led to decreased OPN production and proliferation and increased apoptosis in vitro. MiR-181a treatment of immune competent mice bearing intracranial glioblastoma demonstrated a 22% increase in median survival duration relative to that of control mice.

Radiation with STAT3 Blockade Triggers Dendritic Cell-T cell Interactions in the Glioma Microenvironment and Therapeutic Efficacy.

PURPOSE: Patients with central nervous system (CNS) tumors are typically treated with radiotherapy, but this is not curative and results in the upregulation of phosphorylated STAT3 (p-STAT3), which drives invasion, angiogenesis, and immune suppression. Therefore, we investigated the combined effect of an inhibitor of STAT3 and whole-brain radiotherapy (WBRT) in a murine model of glioma. EXPERIMENTAL DESIGN: C57BL/6 mice underwent intracerebral implantation of GL261 glioma cells, WBRT, and treatment with WP1066, a blood-brain barrier-penetrant inhibitor of the STAT3 pathway, or the two in combination. The role of the immune system was evaluated using tumor rechallenge strategies, immune-incompetent backgrounds, immunofluorescence, immune phenotyping of tumor-infiltrating immune cells (via flow cytometry), and NanoString gene expression analysis of 770 immune-related genes from immune cells, including those directly isolated from the tumor microenvironment. RESULTS: The combination of WP1066 and WBRT resulted in long-term survivors and enhanced median survival time relative to monotherapy in the GL261 glioma model (combination vs. control P < 0.0001). Immunologic memory appeared to be induced, because mice were protected during subsequent tumor rechallenge. The therapeutic effect of the combination was completely lost in immune-incompetent animals. NanoString analysis and immunofluorescence revealed immunologic reprograming in the CNS tumor microenvironment specifically affecting dendritic cell antigen presentation and T-cell effector functions. CONCLUSIONS: This study indicates that the combination of STAT3 inhibition and WBRT enhances the therapeutic effect against gliomas in the CNS by inducing dendritic cell and T-cell interactions in the CNS tumor.

Verteporfin Inhibits PD-L1 through Autophagy and the STAT1-IRF1-TRIM28 Signaling Axis, Exerting Antitumor Efficacy.

Programmed cell death 1 ligand 1 (PD-L1) is a key driver of tumor-mediated immune suppression, and targeting it with antibodies can induce therapeutic responses. Given the costs and associated toxicity of PD-L1 blockade, alternative therapeutic strategies are needed. Using reverse-phase protein arrays to assess drugs in use or likely to enter trials, we performed a candidate drug screen for inhibitors of PD-L1 expression and identified verteporfin as a possible small-molecule inhibitor. Verteporfin suppressed basal and IFN-induced PD-L1 expression in vitro and in vivo through Golgi-related autophagy and disruption of the STAT1-IRF1-TRIM28 signaling cascade, but did not affect the proinflammatory CIITA-MHC II cascade. Within the tumor microenvironment, verteporfin inhibited PD-L1 expression, which associated with enhanced T-lymphocyte infiltration. Inhibition of chromatin-associated enzyme PARP1 induced PD-L1 expression in high endothelial venules (HEV) in tumors and, when combined with verteporfin, enhanced therapeutic efficacy. Thus, verteporfin effectively targets PD-L1 through transcriptional and posttranslational mechanisms, representing an alternative therapeutic strategy for targeting PD-L1.

Chemoprevention with phosphatidylcholine non-steroidal anti-inflammatory drugs in vivo and in vitro.

The chemopreventive activity of non-steroidal anti-inflammatory drugs (NSAIDs), particularly aspirin, has been well demonstrated in preclinical and clinical studies. However, the primary side effect from this class of drug is gastrointestinal (GI) bleeding, which has limited the widespread use of NSAIDs for the prevention of cancer. The development of GI-safer NSAIDs, which are associated with phosphatidylcholine (PC) may provide a solution to this therapeutic problem. In the present study, the efficacy of two NSAIDs, aspirin and indomethacin, were compared using murine colon cancer cell line MC-26. Each NSAID was assessed alone and in combination with PC, using in vitro and in vivo systems. The results reveal that the PC-associated NSAIDs had a significantly higher degree of protection against cancer cell growth compared with the unmodified NSAIDs. It was also observed that Aspirin-PC and Indomethacin-PC prevented the metastatic spread of cancer cells in a syngeneic mouse model. These results support the potential use of PC-NSAIDs for the chemoprevention of colorectal cancer.

ErbB2 promotes Src synthesis and stability: novel mechanisms of Src activation that confer breast cancer metastasis.

Activation of Src kinase plays important roles in the development of many neoplasias. Most of the previous Src studies focused on the deregulation of Src kinase activity. The deregulated Src protein synthesis and stability in mediating malignant phenotypes of cancer cells, however, have been neglected. While investigating the signal transduction pathways contributing to ErbB2-mediated metastasis, we found that ErbB2-activated breast cancer cells that had higher metastatic potentials also had increased Src activity compared with ErbB2 low-expressing cells. The increased Src activity in ErbB2-activated cells paralleled higher Src protein levels, whereas Src RNA levels were not significantly altered. Our studies revealed two novel mechanisms that are involved in Src protein up-regulation and activation by ErbB2: (a) ErbB2 increased Src translation through activation of the Akt/mammalian target of rapamycin/4E-BP1 pathway and (b) ErbB2 increased Src stability most likely through the inhibition of the calpain protease. Furthermore, inhibition of Src activity by a Src-specific inhibitor, PP2, or a Src dominant-negative mutant dramatically reduced ErbB2-mediated cancer cell invasion in vitro and metastasis in an experimental metastasis animal model. Together, activation of ErbB2 and downstream signaling pathways can lead to increased Src protein synthesis and decreased Src protein degradation resulting in Src up-regulation and activation, which play critical roles in ErbB2-mediated breast cancer invasion and metastasis.

Unlocking Aspirin's Chemopreventive Activity: Role of Irreversibly Inhibiting Platelet Cyclooxygenase-1.

The mechanism by which aspirin consumption is linked to significant reductions in the incidence of multiple forms of cancer and metastatic spread to distant tissues, resulting in increased cancer patient survival is not well understood. In this study, using colon cancer as an example, we provide both in vitro (cell culture) and in vivo (chemically induced mouse model of colon cancer) evidence that this profound antineoplastic action may be associated with aspirin's ability to irreversibly inhibit COX-1-mediated platelet activation, thereby blocking platelet-cancer cell interactions, which promote cancer cell number and invasive potential. This process may be driven by platelet-induced epithelial-mesenchymal transition (EMT), as assessed using confocal microscopy, based upon changes in cell morphology, growth characteristics and fibronectin expression, and biochemical/molecular analysis by measuring changes in the expression of the EMT markers; vimentin, ß-catenin, and SNAIL. We also provide evidence that a novel, gastrointestinal-safe phosphatidylcholine (PC)-associated aspirin, PL2200 Aspirin, possesses the same or more pronounced actions versus unmodified aspirin with regard to antiplatelet effects (in vitro: reducing platelet activation as determined by measuring the release of thromboxane and VEGF in culture medium; in vivo: inhibiting platelet number/activation and extravasation into tumor tissue) and chemoprevention (in vitro: inhibiting colonic cell growth and invasive activity; in vivo: inhibiting colonic dysplasia, inflammation, and tumor mass). These results suggest that aspirin's chemopreventive effects may be due, in part, to the drug blocking the proneoplastic action of platelets, and the potential use of Aspirin-PC/PL2200 as an effective and safer chemopreventive agent for colorectal cancer and possibly other cancers. Cancer Prev Res; 10(2); 142-52. ©2016 AACR.

Antitumor and Antiangiogenic Effects of Aspirin-PC in Ovarian Cancer.

To determine the efficacy of a novel and safer (for gastrointestinal tract) aspirin (aspirin-PC) in preclinical models of ovarian cancer, in vitro dose-response studies were performed to compare the growth-inhibitory effect of aspirin-PC versus aspirin on three human (A2780, SKOV3ip1, and HeyA8) and a mouse (ID8) ovarian cancer cell line over an 8-day culture period. In the in vivo studies, the aspirin test drugs were studied alone and in the presence of a VEGF-A inhibitor (bevacizumab or B20), due to an emerging role for platelets in tumor growth following antiangiogenic therapy, and we examined their underlying mechanisms. Aspirin-PC was more potent (vs. aspirin) in blocking the growth of both human and mouse ovarian cancer cells in monolayer culture. Using in vivo model systems of ovarian cancer, we found that aspirin-PC significantly reduced ovarian cancer growth by 50% to 90% (depending on the ovarian cell line). The efficacy was further enhanced in combination with Bevacizumab or B20. The growth-inhibitory effect on ovarian tumor mass and number of tumor nodules was evident, but less pronounced for aspirin and the VEGF inhibitors alone. There was no detectable gastrointestinal toxicity. Both aspirin and aspirin-PC also inhibited cell proliferation, angiogenesis, and increased apoptosis of ovarian cancer cells. In conclusion, PC-associated aspirin markedly inhibits the growth of ovarian cancer cells, which exceeds that of the parent drug, in both cell culture and in mouse model systems. We also found that both aspirin-PC and aspirin have robust antineoplastic action in the presence of VEGF-blocking drugs. Mol Cancer Ther; 15(12); 2894-904. ©2016 AACR.

Incidence of HBV variants with a mutation at nt551 among hepatitis B patients in Nanjing and its neighbourhood.

AIM: To investigate the epidemiology of hepatitis B virus (HBV) strains with a mutation at nt551 in surface gene among hepatitis B patients in Nanjing and its neighbourhood. METHODS: By using mutation-specific polymerase chain reaction (msPCR) established by our laboratory for amplifying HBV DNAs with a mutation at nt551, 117 serum samples taken from hepatitis B patients were detected. RESULTS: The results showed that 112 samples were positive for nt551A, 4 samples were positive for nt551G. One sample was positive for nt551T. No nt551C of HBV DNA was found. The incidence of HBsAg mutants with G, C, T, A at nt551 among 117 samples was 3.42%, 0%, 0.85%, 95.73%, respectively. CONCLUSION: In Nanjing and its neighbourhood, hepatitis B patients are mainly infected with wild genotype HBV. The incidence of mutants with a mutation at nt551 in HBV genome is significantly lower than that in wild genotype HBV DNA (P<0.01). The necessity of adding components of HBsAg mutants to HBV vaccine needs further investigation.