Immunomodulatory Prodrug Micelles Imitate Mild Heat Effects to Reshape Tumor Microenvironment for Enhanced Cancer Immunotherapy.

Physical stimulation with mild heat possesses the notable ability to induce immunomodulation within the tumor microenvironment (TME). It transforms the immunosuppressive TME into an immune-active state, making tumors more receptive to immune checkpoint inhibitor (ICI) therapy. Transient receptor potential vanilloid 1 (TRPV1), which can be activated by mild heat, holds the potential to induce these alterations in the TME. However, achieving precise temperature control within tumors while protecting neighboring tissues remains a significant challenge when using external heat sources. Taking inspiration from the heat sensation elicited by capsaicin-containing products activating TRPV1, this study employs capsaicin to chemically stimulate TRPV1, imitating immunomodulatory benefits akin to those induced by mild heat. This involves developing a glutathione (GSH)-responsive immunomodulatory prodrug micelle system to deliver capsaicin and an ICI (BMS202) concurrently. Following intravenous administration, the prodrug micelles accumulate at the tumor site through the enhanced permeability and retention effect. Within the GSH-rich TME, the micelles disintegrate and release capsaicin and BMS202. The released capsaicin activates TRPV1 expressed in the TME, enhancing programmed death ligand 1 expression on tumor cell surfaces and promoting T cell recruitment into the TME, rendering it more immunologically active. Meanwhile, the liberated BMS202 blocks immune checkpoints on tumor cells and T cells, activating the recruited T cells and ultimately eradicating the tumors. This innovative strategy represents a comprehensive approach to fine-tune the TME, significantly amplifying the effectiveness of cancer immunotherapy by exploiting the TRPV1 pathway and enabling in situ control of immunomodulation within the TME.

Molecularly Targeted Photothermal Ablation of Epidermal Growth Factor Receptor-Expressing Cancer Cells with a Polypyrrole-Iron Oxide-Afatinib Nanocomposite.

Near-infrared-photothermal therapy (NIR-PTT) is a potential modality for cancer treatment. Directing photothermal effects specifically to cancer cells may enhance the therapeutic index for the best treatment outcome. While epithelial growth factor receptor (EGFR) is commonly overexpressed/genetically altered in human malignancy, it remains unknown whether targeting EGFR with tyrosine kinase inhibitor (TKI)-conjugated nanoparticles may direct NIR-PTT to cancers with cellular precision. In the present study, we tested this possibility through the fabrication of a polypyrrole-iron oxide-afatinib nanocomposite (PIA-NC). In the PIA-NC, a biocompatible and photothermally conductive polymer (polypyrrole) was conjugated to a TKI (afatinib) that binds to overexpressed wild-type EGFR without overt cytotoxicity. A Fenton catalyst (iron oxide) was further encapsulated in the NC to drive the intracellular ROS surge upon heat activation. Diverse physical and chemical characterization experiments were conducted. Particle internalization, cytotoxicity, ROS production, and apoptosis in EGFR-positive and -negative cell lines were investigated in the presence and absence of NIR. We found that the PIA-NCs were stable with a size of 243 nm and a zeta potential of +35 mV. These PIA-NCs were readily internalized close to the cell membrane by all types of cells used in the study. The Fourier transform infrared spectra showed 3295 cm-1 peaks; substantial O-H stretching was seen, with significant C=C stretching at 1637 cm-1; and a modest appearance of C-O-H bending at 1444 cm-1 confirmed the chemical conjugation of afatinib but not iron oxide to the NC. At a NIR-PTT energy level that has a minimal cytotoxic effect, PIA-NC significantly sensitizes EGFR-overexpressing A549 lung cancer cells to NIR-PTT-induced cytotoxicity at a rate of 70%, but in EGFR-negative 3T3 fibroblasts the rate was 30%. Within 1 min of NIR-PTT, a surge of intracellular ROS was found in PIA-NC-treated A549 cells. This was followed by early induction of cellular apoptosis for 54 ± 0.081% of A549 cells. The number of viable cells was less than a quarter of a percent. Viability levels of A549 cells that had been treated with NIR or PIA were only 50 ± 0.216% and 80 ± 0.216%, respectively. Only 10 ± 0.816% of NIH3T3 cells had undergone necrosis, meaning that 90 ± 0.124% were alive. Viability levels were 65 ± 0.081% and 81 ± 0.2%, respectively, when only NIR and PIA were used. PIA binding was effective against A549 cells but not against NIH3T3 cells. The outcome revealed that higher levels of NC + NIR exposure caused cancer cells to produce more ROS. In summary, our findings proved that a molecularly targeted NC provides an orchestrated platform for cancer cell-specific delivery of NIR-PTT. The geometric proximity design indicates a novel approach to minimizing the off-target biological effects of NIR-PTT. The potential of PIA-NC to be further developed into real-world application warrants further investigation.

Modulation of tumor microenvironment using a TLR-7/8 agonist-loaded nanoparticle system that exerts low-temperature hyperthermia and immunotherapy for in situ cancer vaccination.

Most cancer vaccines under development are associated with defined tumor antigens rather than with all antigens of whole tumor cells, limiting the anti-tumor immune responses that they elicit. This work proposes an immunomodulator (R848)-loaded nanoparticle system (R848@NPs) that can absorb near-infrared light (+NIR) to cause low-temperature hyperthermia that interacts synergistically with its loaded R848 to relieve the tumor-mediated immunosuppressive microenvironment, generating robust anti-tumor memory immunity. In vitro results reveal that the R848@NPs could be effectively internalized by dendritic cells, causing their maturation and the subsequent regulation of their anti-tumor immune responses. Post-treatment observations in mice in which tumors were heat-treated at high temperatures reveal that tumor growth was significantly inhibited initially but not in the longer term, while low-temperature hyperthermia or immunotherapy alone simply delayed tumor growth. In contrast, a combined therapy that involved low-temperature hyperthermia and immunotherapy using R848@NPs/+NIR induced a long-lasting immunologic memory and consequently inhibited tumor growth and prevented cancer recurrence and metastasis. These results suggest that the method that is proposed herein is promising for generating cancer vaccines in situ, by using the tumor itself as the antigen source and the introduced R848@NPs/+NIR to generate a long-term anti-tumor immunity, for personalized immunotherapy.

Acidity-triggered charge-convertible nanoparticles that can cause bacterium-specific aggregation in situ to enhance photothermal ablation of focal infection.

Focal infections that are caused by antibiotic-resistant bacteria are becoming an ever-growing challenge to human health. To address this challenge, a pH-responsive amphiphilic polymer of polyaniline-conjugated glycol chitosan (PANI-GCS) that can self-assemble into nanoparticles (NPs) in situ is developed. The PANI-GCS NPs undergo a unique surface charge conversion that is induced by their local pH, favoring bacterium-specific aggregation without direct contact with host cells. Following conjugation onto GCS, the optical-absorbance peak of PANI is red-shifted toward the near-infrared (NIR) region, enabling PANI-GCS NPs to generate a substantial amount of heat, which is emitted to their neighborhood. The local temperature of the NIR-irradiated PANI-GCS NPs is estimated to be approximately 5 °C higher than their ambient tissue temperature, ensuring specific and direct heating of their aggregated bacteria; hence, damage to tissue is reduced and wound healing is accelerated. The above results demonstrate that PANI-GCS NPs are practical for use in the photothermal ablation of focal infections.

Localized sequence-specific release of a chemopreventive agent and an anticancer drug in a time-controllable manner to enhance therapeutic efficacy.

Combination chemotherapy with multiple drugs commonly requires several injections on various schedules, and the probability that the drug molecules reach the diseased tissues at the proper time and effective therapeutic concentrations is very low. This work elucidates an injectable co-delivery system that is based on cationic liposomes that are adsorbed on anionic hollow microspheres (Lipos-HMs) via electrostatic interaction, from which the localized sequence-specific release of a chemopreventive agent (1,25(OH)2D3) and an anticancer drug (doxorubicin; DOX) can be thermally driven in a time-controllable manner by an externally applied high-frequency magnetic field (HFMF). Lipos-HMs can greatly promote the accumulation of reactive oxygen species (ROS) in tumor cells by reducing their cytoplasmic expression of an antioxidant enzyme (superoxide dismutase) by 1,25(OH)2D3, increasing the susceptibility of cancer cells to the cytotoxic action of DOX. In nude mice that bear xenograft tumors, treatment with Lipos-HMs under exposure to HFMF effectively inhibits tumor growth and is the most effective therapeutic intervention among all the investigated. These empirical results demonstrate that the synergistic anticancer effects of sequential release of 1,25(OH)2D3 and DOX from the Lipos-HMs may have potential for maximizing DOX cytotoxicity, supporting more effective cancer treatment.

Enhancement of cell adhesion, retention, and survival of HUVEC/cbMSC aggregates that are transplanted in ischemic tissues by concurrent delivery of an antioxidant for therapeutic angiogenesis.

A recurring obstacle in cell-base strategies for treating ischemic diseases is the significant loss of viable cells that is caused by the elevated levels of regional reactive oxygen species (ROS), which ultimately limits therapeutic capacity. In this study, aggregates of human umbilical vein endothelial cells (HUVECs) and cord-blood mesenchymal stem cells (cbMSCs), which are capable of inducing therapeutic angiogenesis, are prepared. We hypothesize that the concurrent delivery of an antioxidant N-acetylcysteine (NAC) may significantly increase cell retention following the transplantation of HUVEC/cbMSC aggregates in a mouse model with hindlimb ischemia. Our in vitro results demonstrate that the antioxidant NAC can restore ROS-impaired cell adhesion and recover the reduced angiogenic potential of HUVEC/cbMSC aggregates under oxidative stress. In the animal study, we found that by scavenging the ROS generated in ischemic tissues, NAC is likely to be able to establish a receptive cell environment in the early stage of cell transplantation, promoting the adhesion, retention, and survival of cells of engrafted aggregates. Therapeutic angiogenesis is therefore enhanced and blood flow recovery and limb salvage are ultimately achieved. The combinatory strategy that uses an antioxidant and HUVEC/cbMSC aggregates may provide a new means of boosting the therapeutic efficacy of cell aggregates for the treatment of ischemic diseases.

Synergistic antibacterial effects of localized heat and oxidative stress caused by hydroxyl radicals mediated by graphene/iron oxide-based nanocomposites.

This work develops a composite system of reduced graphene oxide (rGO)-iron oxide nanoparticles (rGO-IONP) that can synergistically induce physical and chemical damage to methicillin-resistant Staphylococcus aureus (MRSA) that are present in subcutaneous abscesses. rGO-IONP was synthesized by the chemical deposition of Fe(2+)/Fe(3+) ions on nanosheets of rGO in aqueous ammonia. The antibacterial efficacy of the as-prepared rGO-IONP was evaluated in a mouse model with MRSA-infected subcutaneous abscesses. Upon exposure to a near-infrared laser in vitro, rGO-IONP synergistically generated localized heat and large amounts of hydroxyl radicals, which inactivated MRSA. The in vivo results reveal that combined treatment with localized heat and oxidative stress that is caused by hydroxyl radicals accelerated the healing of wounds associated with MRSA-infected abscesses. The above results demonstrate that an rGO-IONP nanocomposite system that can effectively inactivate multiple-drug-resistant bacteria in subcutaneous infections was successfully developed. FROM THE CLINICAL EDITOR: The emergence of methicillin-resistant S. aureus (MRSA) has posed a significant problem in the clinical setting. Thus, it is imperative to develop new treatment strategies against this. In this study, the authors described the use of reduced graphene oxide (rGO)-iron oxide nanoparticles (rGO-IONP) to induce heat and chemical damage to MRSA. This approach may provide a platform the design of other treatment modalities against multiple-drug-resistant bacteria.

Multimodality noninvasive imaging for assessing therapeutic effects of exogenously transplanted cell aggregates capable of angiogenesis on acute myocardial infarction.

Although the induction of neovascularization by cell-based approaches has demonstrated substantial potential in treating myocardial infarction (MI), the process of cell-mediated angiogenesis and its correlation with therapeutic mechanisms of cardiac repair remain elusive. In this work, three-dimensional (3D) aggregates of human umbilical vein endothelial cells (HUVECs) and cord-blood mesenchymal stem cells (cbMSCs) are constructed using a methylcellulose hydrogel system. By maximizing cell-cell and cell-ECM communications and establishing a hypoxic microenvironment in their inner cores, these cell aggregates are capable of forming widespread tubular networks together with the angiogenic marker αvß3 integrin; they secret multiple pro-angiogenic, pro-survival, and mobilizing factors when grown on Matrigel. The aggregates of HUVECs/cbMSCs are exogenously engrafted into the peri-infarct zones of rats with MI via direct local injection. Multimodality noninvasive imaging techniques, including positron emission tomography, single photon emission computed tomography, and echocardiography, are employed to monitor serially the beneficial effects of cell therapy on angiogenesis, blood perfusion, and global/regional ventricular function, respectively. The myocardial perfusion is correlated with ventricular contractility, demonstrating that the recovery of blood perfusion helps to restore regional cardiac function, leading to the improvement in global ventricular performance. These experimental data reveal the efficacy of the exogenous transplantation of 3D cell aggregates after MI and elucidate the mechanism of cell-mediated therapeutic angiogenesis for cardiac repair.

Gene expression profiling for analysis acquired oxaliplatin resistant factors in human gastric carcinoma TSGH-S3 cells: the role of IL-6 signaling and Nrf2/AKR1C axis identification.

Oxaliplatin treatment is a mainstay of treatment for advanced gastrointestinal tract cancer, but the underlying mechanisms of acquired oxaliplatin resistance remain largely obscured. We previously demonstrated that increased DNA repair capacity and copper-transporting ATPase 1 (ATP7A) level contributed to oxaliplatin resistance in the human gastric carcinoma cell line TSGH-S3 (S3). In the present study, we applied gene array technology to identify additional resistance factors in S3 cells. We found that interleukin-6 (IL-6), aldo-keto reductase 1C1 (AKR1C1), and AKR1C3 are the top 3 upregulated genes in S3 cells when compared with parent TSGH cells. Despite a higher level of endogenous IL-6 in S3, IL-6 receptor (IR-6R, gp-80, and gp-130) levels were similar between TSGH and S3 cells. The addition of exogenous IL-6, IL-6 targeted siRNA, or neutralizing antibodies neither affected Stat3 activation, a downstream target of IL-6, nor changed oxaliplatin sensitivity in S3 cells. However, manipulation of AKR1C activity with siRNA or AKR1C inhibitors significantly reversed oxaliplatin resistance. AKR1Cs are classical antioxidant response element (ARE) genes that can be transcriptionally upregulated by nuclear factor erythroid 2-related factor 2 (Nrf2). Knockdown of Nrf2 not only decreased the levels of AKR1C1, AKR1C2, and AKR1C3 mRNA and protein but also reversed oxaliplatin resistance in S3 cells. Taken together, these results suggest that activation of the Nrf2/AKR1C axis may contribute to oxaliplatin resistance in S3 cells but that the IL-6 signaling pathway did not contribute to resistance. Manipulation of Nrf2/AKR1Cs activity may be useful for management of oxaliplatin-refractory gastric cancers.

MPT0B098, a novel microtubule inhibitor that destabilizes the hypoxia-inducible factor-1α mRNA through decreasing nuclear-cytoplasmic translocation of RNA-binding protein HuR.

Microtubule inhibitors have been shown to inhibit hypoxia-inducible factor-1α (HIF-1α) expression through inhibition translation or enhancing protein degradation. Little is known of the effect of microtubule inhibitors on the stability of HIF-1α mRNA. We recently discovered a novel indoline-sulfonamide compound, 7-aryl-indoline-1-benzene-sulfonamide (MPT0B098), as a potent microtubule inhibitor through binding to the colchicine-binding site of tubulin. MPT0B098 is active against the growth of various human cancer cells, including chemoresistant cells with IC50 values ranging from 70 to 150 nmol/L. However, normal cells, such as human umbilical vein endothelial cells (HUVEC), exhibit less susceptibility to the inhibitory effect of MPT0B098 with IC50 of 510 nmol/L. Similar to typical microtubule inhibitors, MPT0B098 arrests cells in the G2-M phase and subsequently induces cell apoptosis. In addition, MPT0B098 effectively suppresses VEGF-induced cell migration and capillary-like tube formation of HUVECs. Distinguished from other microtubule inhibitors, MPT0B098 not only inhibited the expression levels of HIF-1α protein but also destabilized HIF-1α mRNA. The mechanism of causing unstable of HIF-1α mRNA by MPT0B098 is through decreasing RNA-binding protein, HuR, translocation from the nucleus to the cytoplasm. Notably, MPT0B098 effectively suppresses tumor growth and microvessel density of tumor specimens in vivo. Taken together, our results provide a novel mechanism of inhibiting HIF-1α of a microtubule inhibitor MPT0B098. MPT0B098 is a promising anticancer drug candidate with potential for the treatment of human malignancies.

Cancer immunotherapy using a membrane-bound interleukin-12 with B7-1 transmembrane and cytoplasmic domains.

Interleukin-12 (IL-12) has potent antitumor activity, but its clinical application is limited by severe systemic toxicity, which might be alleviated by the use of membrane-anchored IL-12. In the present study, a new membrane-bound IL-12 containing murine single-chain IL-12 and B7-1 transmembrane and cytoplasmic domains (scIL-12-B7TM) was constructed and its efficacy in cancer treatment examined and its protective antitumor mechanism investigated. Surface expression of scIL-12-B7TM on colon adenocarcinoma cells significantly inhibited the growth of subcutaneous tumors, suppressed lung metastasis, and resulted in local and systemic suppression of unmodified tumors. Intratumoral injection of an adenoviral vector encoding scIL-12-B7TM not only resulted in complete regression of a majority of local tumors, but also significantly suppressed the growth of distant, untreated tumors. Moreover, mice that had been treated with scIL-12-B7TM developed memory responses against subsequent tumor challenge. Immunohistochemical staining and in vivo depletion of lymphocyte subpopulations demonstrated that both CD8(+) T cells and CD4(+) T cells contributed to the antitumor activity of scIL-12-B7TM. Importantly, the potent antitumor activities of scIL-12-B7TM were achieved with only negligible amounts of IL-12 in the circulation. Our data demonstrate that cancer immunotherapy using membrane-bound IL-12 has the advantage of minimizing systemic IL-12 levels without compromising its antitumor efficacy.

Combination of arsenic trioxide and BCNU synergistically triggers redox-mediated autophagic cell death in human solid tumors.

Arsenic trioxide (As(2)O(3)) is an effective treatment for relapsed or refractory acute promyelocytic leukemia (APL). After the discovery of As(2)O(3) as a promising treatment for APL, several studies investigated the use of As(2)O(3) as a single agent in the treatment of solid tumors; however, its therapeutic efficacy is limited. Thus, the systematic study of the combination of As(2)O(3) with other clinically used chemotherapeutic drugs to improve its therapeutic efficacy in treating human solid tumors is merited. In this study, we demonstrate for the first time, using isobologram analysis, that As(2)O(3) exhibits a synergistic interaction with N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU). The synergistic augmentation of the cytotoxicity of As(2)O(3) with BCNU is in part through the autophagic cell death machinery in human solid tumor cells. As(2)O(3) and BCNU in combination produce enhanced cytotoxicity via the depletion of reduced glutathione (GSH) and augmentation of reaction oxygen species (ROS) production. Further analysis indicated that the extension of GSH depletion by this combined regimen occurs through the inhibition of the catalytic activity of glutathione reductase. Blocking ROS production with antioxidants or ROS scavengers effectively inhibits cell death and autophagy formation, indicating that redox-mediated autophagic cell death involves the synergism of As(2)O(3) with BCNU. Taken together, this is the first evidence that BCNU could help to extend the therapeutic spectrum of As(2)O(3). These findings will be useful in designing future clinical trials of combination chemotherapy with As(2)O(3) and BCNU, with the potential for broad use against a variety of solid tumors.

A murine model of hepatitis B-associated hepatocellular carcinoma generated by adeno-associated virus-mediated gene delivery.

A relevant animal model is critical for investigating the pathogenic mechanisms underlying hepatitis B virus (HBV)-induced hepatocellular carcinoma (HCC). Mice are not naturally infected by HBV, presumably due to the lack of HBV receptors on mouse hepatocytes. To bypass this entry step of HBV infection, we report generation of a novel HBV model in immunocompetent mice by hepatic delivery of the HBV genome using trans-splicing adeno-associated viral vectors (AAV/HBV). We confirmed production of HBV virions and proteins in the liver and circulation in all AAV/HBV-transduced mice in all four immunocompetent mouse strains tested. These mice produced antigen and antibody profiles similar to that observed in chronic HBV patients. Importantly, 12-16 months later, all 12 AAV/HBV-transduced mice developed macroscopically visible liver-tumor nodules. Ten of the twelve tumors were characterized with typical HCC features. This AAV/HBV-transduced murine HCC model provides a useful instrument for studying the pathogenesis of HBV-associated HCC and the development of HCC therapeutic interventions.

Enhancement of non-homologous end joining DNA repair capacity confers cancer cells resistance to the novel selenophene compound, D-501036.

D-501036 is a promising anti-cancer compound that exhibits potent anti-proliferative activity against various types of human cancers through the induction of double strand DNA breaks. To determine drug resistance mechanism related to this class of DNA-damaging agents, a KB-derived D-501036-resistant cell line (S4) was established. Results showed that S4 cells exhibit enhanced DNA rejoining ability as compare to KB cells, through up-regulation of the non-homologous end joining activity. In conclusion, enhancement of NHEJ activity plays important role in the development of D-501036-resistance and targeting NHEJ-related molecules maybe able to overcome drug resistance to DNA damaging agents.

2-amino-3,4,5-trimethoxybenzophenones as potent tubulin polymerization inhibitors.

A series of novel 2-amino-3,4,5-trimethoxybenzophenone analogues exhibited excellent activity as tubulin polymerization inhibitors by targeting the colchicine binding site of microtubules. The lead compound 17 exhibited an IC50 value of 1.6 µM, similar to that of combretastatin A-4 (IC50=1.9 µM). It also displayed remarkable anti-proliferative activity, with IC50 values ranging from 7-16 nM against a variety of human cancer cell lines and one MDR(+) cancer cell line. SAR information indicated that the introduction of an amino group at the C2 position of benzophenone ring A and the C3' position of benzophenone ring B play important roles in maximizing activity.

Hydrogel-delivered GM-CSF overcomes nonresponsiveness to hepatitis B vaccine through the recruitment and activation of dendritic cells.

The standard hepatitis B surface Ag (HBsAg) vaccine fails to induce anti-hepatitis B surface Abs in 5-10% of healthy subjects, a phenomenon known as HBsAg nonresponsiveness, which is closely related to HLA class II alleles and impaired Th cell responses to HBsAg in these subjects. We hypothesized that GM-CSF, a potent adjuvant in enhancing the Ag-presentation activity of APCs, might help to generate Th cell responses in nonresponders, subsequently providing help for B cells to produce anti-hepatitis B surface Abs. We used a thermosensitive biodegradable copolymer (hydrogel) system to codeliver HBsAg and GM-CSF to achieve maximal local cytokine activity at the injection site. In responder mouse strains, hydrogel-formulated HBsAg plus GM-CSF (Gel/HBs+GM) vaccine elicited much greater anti-hepatitis B surface Ab titers and Th cell proliferative responses than a commercial aluminum-formulated HBsAg vaccine or free HBsAg. The adjuvant effect of the Gel/HBs+GM vaccine was dependent upon the local release of GM-CSF. More importantly, the Gel/HBs+GM vaccine elicited high HBsAg-specific Ab titers and Th cell responses in B10.M mice, a mouse strain that does not respond to the current HBsAg vaccine because of its H-2 haplotype. Analysis of the draining lymph nodes of Gel/HBs+GM vaccine-treated mice revealed an elevated number of CD11c(+) dendritic cells showing enhanced expression of MHC class II and a variety of costimulatory molecules. These results demonstrate that hydrogel-formulated GM-CSF might represent a simple and effective method to generate next-generation hepatitis B virus vaccines for inducing anti-hepatitis B surface Abs in nonresponders.

Differential antitumor effect of interleukin-12 family cytokines on orthotopic hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most difficult cancers to treat. The interleukin (IL)-12 family cytokines, including IL-12, IL-23 and IL-27, display overlapping, but not redundant, roles in regulating lymphocyte subpopulations. IL-12 is known as a potent antitumor cytokine, whereas the results of the antitumor effect of IL-23 and IL-27 are inconsistent. The present study aimed to directly compare the relative antitumor efficacy of these three IL-12 family cytokines on HCC. METHODS: A murine orthotopic BNL HCC model, in which the tumor is located in an environment heavily populated with different lymphocyte subsets, was established. The hepatotropic adeno-associated virus serotype 8 (AAV8) vector was used to deliver the cytokine genes aiming to achieve sustained cytokine expression in the liver. RESULTS: AAV8/IL-12 treatment significantly reduced hepatic metastases and prolonged survival time, whereas treatment with AAV8/IL-23 or AAV8/IL-27 had only moderate antitumor effects at a high dose. The antitumor efficacy of these cytokines was positively correlated with their ability to regulate hepatic T cells, natural killer cells and natural killer T cells, with IL-12 greatly increasing the number and activation status of these cells, whereas IL-27 had no effect and IL-23 had a negative effect. AAV8/IL-12 treatment also resulted in a marked decrease in tumor vessel density, which was not observed with AAV8/IL-23 and AAV8/IL-27 treatment. CONCLUSIONS: The data obtained in the present study highlight the importance of local lymphocytes and anti-angiogenesis for influencing the antitumor activity of these three IL-12 family cytokines and suggest that IL-12 is the best candidate for treating HCC.

Chamaecypanone C, a novel skeleton microtubule inhibitor, with anticancer activity by trigger caspase 8-Fas/FasL dependent apoptotic pathway in human cancer cells.

Microtubule is a popular target for anticancer drugs. Chamaecypanone C, is a natural occurring novel skeleton compound isolated from the heartwood of Chamaecyparis obtusa var. formosana. The present study demonstrates that chamaecypanone C induced mitotic arrest through binding to the colchicine-binding site of tubulin, thus preventing tubulin polymerization. In addition, cytotoxic activity of chamaecypanone C in a variety of human tumor cell lines has been ascertained, with IC(50) values in nanomolar ranges. Flow cytometric analysis revealed that chamaecypanone C treated human KB cancer cells were arrested in G(2)-M phases in a time-dependent manner before cell death occurred. Additional studies indicated that the effect of Chamaecypanone C on cell cycle arrest was associated with an increase in cyclin B1 levels and a mobility shift of Cdc2/Cdc25C. The changes in Cdc2 and Cdc25C coincided with the appearance of phosphoepitopes recognized by a marker of mitosis, MPM-2. Interestingly, this compound induced apoptotic cell death through caspase 8-Fas/FasL dependent pathway, instead of mitochondria/caspase 9-dependent pathway. Notably, several KB-derived multidrug resistant cancer cell lines overexpressing P-gp170/MDR and MRP were sensitive to Chamaecypanone C. Taken together, these findings indicated that Chamaecypanone C is a promising anticancer compound that has potential for management of various malignancies, particularly for patients with drug resistance.

Synthesis and structure-activity relationships of 1-benzyl-4,5,6-trimethoxyindoles as a novel class of potent antimitotic agents.

A series of 1-benzyl-4,5,6-trimethoxyindoles was designed and prepared as a novel class of potent antimitotic agents acting through the colchicine binding site of tubulin. Compounds 10 and 11 showed excellent antiproliferative activity with mean IC(50) values of 26 and 27 nM, respectively, in a diverse set of human cancer lines from different organs, including a MDR+ line. They also displayed substantial antitubulin efficacy with IC(50) values of 3.5 and 2.6 muM, respectively, representing an improvement over colchicine (IC(50)=4.3 muM).

A novel peroxisome proliferator-activated receptor alpha/gamma agonist, BPR1H0101, inhibits topoisomerase II catalytic activity in human cancer cells.

Peroxisome proliferator-activated receptor (PPAR) gamma agonists are used clinically for treating diabetes mellitus and cancer. 2-Methyl-2[(1-{3-phenyl-7-propylbenzol[d]isoxazol-6-yl}oxy)propyl]-1H-4-indolyl) oxy]propanoic acid (BPR1H0101) is a novel synthetic indole-based compound, discovered through research to identify new PPARgamma agonists, and it acts as a dual agonist for PPARgamma and PPARalpha. Isobologram analysis demonstrated that BPR1H0101 is capable of antagonistic interaction with the topoisomerase (topo) II poison, VP16. A study of its mechanism showed that BPR1H0101 could inhibit the catalytic activity of topo II in vitro, but did not produce detectable topo II-mediated DNA strand breaks in human oral cancer KB cells. Furthermore, BPR1H0101 could inhibit VP16-induced topo II-mediated DNA cleavage and ataxia-telangiectasia-mutated phosphorylation in KB cells. The results suggest that BPR1H0101 can interfere with the topo II reaction by inhibiting catalytic activity before the formation of the intermediate cleavable complex; consequently, it can impede VP16-induced topo II-mediated DNA cleavage and cell death. This is the first identified PPARalpha/gamma agonist that can serve as a topo II catalytic inhibitor, to interfere with VP16-induced cell death. The result might have relevance to the clinical use of the PPARalpha/gamma agonist in combination chemotherapy.