Cisplatin combined with laser­activated nanotherapy as an adjuvant therapy for head and neck cancer.

Head and neck cancers (HNCs), in general, have a poor prognosis with a worldwide 5­year survival rate of <50%. Numerous HNC patients with locoregionally advanced, difficult­to­treat, inoperable, recurrent and drug­resistant tumors may require additional treatment options when the standard of care surgery, chemotherapy and radiation are not viable. The poor outcomes justify exploring strategies to increase the efficacy of lower doses of drugs, such as cisplatin, by combining these drugs with other treatment modalities and manipulating the dosing schedule. Cisplatin is a standard and effective anticancer drug; however, some patients cannot tolerate the side­effects or exhibit drug resistance. Adjuvant therapies may lower the effective dose, decrease side­effects, address drug resistance and improve overall survival outcomes, particularly for patients with difficult­to­treat tumors. The present study focuses on combining cisplatin with laser­activated nanotherapy (LANT), as an adjuvant HNC therapy, with the aim of enhancing the therapeutic efficacy of lower doses of cisplatin and decreasing treatment times. The results demonstrate the potential of cisplatin and LANT co­therapy as a possible addition to the adjuvant therapy options for HNC using 3 cell lines: Detroit 562, FaDu and CAL 27 cells. Combining cisplatin with LANT demonstrated up to a 5.4­fold greater therapeutic efficacy than with cisplatin monotreatment. The most effective combination in the present study was 1 µM Cis + 5 nM LANT, which demonstrated cell death comparable to 5.9, 4.2 and 5.3 µM of Cis monotreatment, in Detroit 562, FaDu and CAL 27 cells, respectively. This result suggests that a lower cisplatin dose may be combined with LANT to achieve the same therapeutic efficacy as that obtained with higher doses of cisplatin monotreatment. The combination of LANT and cisplatin suggests that LANT may enhance the therapeutic efficiency of low doses of cisplatin, decrease treatment times and improve patient outcomes.

Quantitative Examination of the Active Targeting Effect: The Key Factor for Maximal Tumor Accumulation and Retention of Short-Circulated Biopolymeric Nanocarriers.

Targeted and nontargeted biopolymeric nanoparticles with identical hydrodynamic sizes and surface charges were quantitatively examined in terms of the pharmacokinetic and biodistribution differences in detail. In adding cancer cell targeting folate molecules to the surface of the heparin nanocarriers, the amount of drug delivered to the tumor is doubled, and tumor growth inhibition is significantly enhanced. The folate-targeted heparin particles offered similar therapeutic potentials compared to their synthetic long-circulating analogues, thus presenting a viable alternative for drug-delivery vehicle construction using biological polymers, which are easier for the body to eliminate.

Functionalized, Long-Circulating, and Ultrasmall Gold Nanocarriers for Overcoming the Barriers of Low Nanoparticle Delivery Efficiency and Poor Tumor Penetration.

The development of sophisticated nanoplatforms for in vivo targeted delivery of therapeutic agents to solid tumors has the potential for not only improving therapeutic efficacy but also minimizing systemic toxicity. However, the currently low delivery efficiency (about 1% of the injected dose) and the limited tumor penetration of nanoparticles remain two major challenges. Here we report a class of functionalized, long-circulating, and ultrasmall gold nanocarriers (5 nm gold core and 20 nm overall hydrodynamic diameter) for improved drug delivery and deep tumor penetration. By using doxorubicin as a model drug, our design also includes a pH-sensitive hydrazone linkage that is stable at neutral or slightly basic pH but is rapidly cleaved in the acidic tumor microenvironments and intracellular organelles. With a circulation halftime of 1.6 days, the small particle size is an important feature not only for efficient extravasation and accumulation via the enhanced permeability and retention (EPR) effect, but also for faster nanoparticle diffusion and improved tumor penetration. In xenograft animal models, the results demonstrate that up to 8% of the injected nanoparticles can be accumulated at the tumor sites, among the highest nanoparticle delivery efficiencies reported in the literature. Also, histopathological and direct visual examinations reveal dark-colored tumors with deep nanoparticle penetration and distribution throughout the tumor mass. In comparison with pure doxorubicin which is known to cause considerable heart, kidney, and lung toxicity, in vivo animal data indicate that this class of functionalized and ultrasmall gold nanoparticles indeed provides better therapeutic efficacies with no apparent toxicity in vital organs.

An unusual role of folate in the self-assembly of heparin-folate conjugates into nanoparticles.

Tumor targeting agents including antibodies, peptides, and small molecules, are often used to improve the delivery efficiency of nanoparticles. Despite numerous studies investigating the abilities of targeting agents to increase the accumulation of nanosized therapeutics within diseased tissues, little attention has been focused on how these ligands can affect the self-assembly of the nanoparticle's modified polymer constituents upon chemical conjugation. Here we present an actively tumor targeted nanoparticle constructed via the self-assembly of a folate modified heparin. Folate conjugation unexpectedly allowed the self-assembly of heparin, where a majority of the folate molecules (>80%) resided inside the core of the nanoparticle. The folate-heparin nanoparticles could also physically encapsulate lipophilic fluorescent dyes, enabling the use of the constructs as activatable fluorescent probes for targeted in vivo tumor imaging.

Expression and functional validation of heat-labile enterotoxin B (LTB) and cholera toxin B (CTB) subunits in transgenic rice (Oryza sativa).

We expressed the heat-labile enterotoxin B (LTB) subunit from enterotoxigenic Escherichia coli and the cholera toxin B (CTB) subunit from Vibrio cholerae under the control of the rice (Oryza sativa) globulin (Glb) promoter. Binding of recombinant LTB and CTB proteins was confirmed based on GM1-ganglioside binding enzyme-linked immunosorbent assays (GM1-ELISA). Real-time PCR of three generations (T3, T4, and T5) in homozygous lines (LCI-11) showed single copies of LTB, CTB, bar and Tnos. LTB and CTB proteins in rice transgenic lines were detected by Western blot analysis. Immunogenicity trials of rice-derived CTB and LTB antigens were evaluated through oral and intraperitoneal administration in mice, respectively. The results revealed that LTB- and CTB-specific IgG levels were enhanced in the sera of intraperitoneally immunized mice. Similarly, the toxin-neutralizing activity of CTB and LTB in serum of orally immunized mice was associated with elevated levels of both IgG and IgA. The results of the present study suggest that the combined expression of CTB and LTB proteins can be utilized to produce vaccines against enterotoxigenic strains of Escherichia coli and Vibrio cholera, for the prevention of diarrhea.

Exercise-induced lung cancer regression: mechanistic findings from a mouse model.

BACKGROUND: It has been demonstrated that regular exercise improves the quality of life in patients undergoing treatment for lung cancer and has been associated with reductions in cancer-specific mortality in patients with colon and breast cancer. The direct effects of cardiovascular exercise on lung cancer tumor biology, however, remain unknown. The authors evaluated the effects of cardiovascular exercise in a mouse model of lung adenocarcinoma. METHODS: Luciferase-tagged A549 lung adenocarcinoma cells were injected through the tail vein of nude male mice. Then, the mice underwent weekly bioluminescent imaging until lung tumors were clearly identified. After lung tumors were identified, the mice were randomized to daily wheel running versus no wheel running, and they were imaged weekly. After 4 weeks, all mice were killed, and the lung tumors were harvested. Western blot and immunohistochemical analyses were conducted on tumor tissues to identify potential differences in protein expression levels in exercising mice versus sedentary mice. RESULTS: Lung tumors in exercising mice grew significantly more slowly relative to sedentary mice. There was no change in the development of metastatic lesions between the 2 groups. Protein analysis by Western blot or immunohistochemical analysis demonstrated increased p53 protein levels in exercising mice relative to sedentary mice as well as increased mediators of apoptosis, including Bax and active caspase 3, in tumor tissues. In both groups of mice, no normal tissue toxicity was observed in other organs. CONCLUSIONS: Daily cardiovascular exercise appears to mitigate the growth of lung adenocarcinoma tumors, possibly by activation of the p53 tumor suppressor function and increased apoptosis.

Active targeting using HER-2-affibody-conjugated nanoparticles enabled sensitive and specific imaging of orthotopic HER-2 positive ovarian tumors.

Despite advances in cancer diagnosis and treatment, ovarian cancer remains one of the most fatal cancer types. The development of targeted nanoparticle imaging probes and therapeutics offers promising approaches for early detection and effective treatment of ovarian cancer. In this study, HER-2 targeted magnetic iron oxide nanoparticles (IONPs) are developed by conjugating a high affinity and small size HER-2 affibody that is labeled with a unique near infrared dye (NIR-830) to the nanoparticles. Using a clinically relevant orthotopic human ovarian tumor xenograft model, it is shown that HER-2 targeted IONPs are selectively delivered into both primary and disseminated ovarian tumors, enabling non-invasive optical and MR imaging of the tumors as small as 1 mm in the peritoneal cavity. It is determined that HER-2 targeted delivery of the IONPs is essential for specific and sensitive imaging of the HER-2 positive tumor since we are unable to detect the imaging signal in the tumors following systemic delivery of non-targeted IONPs into the mice bearing HER-2 positive SKOV3 tumors. Furthermore, imaging signals and the IONPs are not detected in HER-2 low expressing OVCAR3 tumors after systemic delivery of HER-2 targeted-IONPs. Since HER-2 is expressed in a high percentage of ovarian cancers, the HER-2 targeted dual imaging modality IONPs have potential for the development of novel targeted imaging and therapeutic nanoparticles for ovarian cancer detection, targeted drug delivery, and image-guided therapy and surgery.

Theranostic nanoparticles with controlled release of gemcitabine for targeted therapy and MRI of pancreatic cancer.

The tumor stroma in human cancers significantly limits the delivery of therapeutic agents into cancer cells. To develop an effective therapeutic approach overcoming the physical barrier of the stroma, we engineered urokinase plasminogen activator receptor (uPAR)-targeted magnetic iron oxide nanoparticles (IONPs) carrying chemotherapy drug gemcitabine (Gem) for targeted delivery into uPAR-expressing tumor and stromal cells. The uPAR-targeted nanoparticle construct, ATF-IONP-Gem, was prepared by conjugating IONPs with the amino-terminal fragment (ATF) peptide of the receptor-binding domain of uPA, a natural ligand of uPAR, and Gem via a lysosomally cleavable tetrapeptide linker. These theranostic nanoparticles enable intracellular release of Gem following receptor-mediated endocytosis of ATF-IONP-Gem into tumor cells and also provide contrast enhancement in magnetic resonance imaging (MRI) of tumors. Our results demonstrated the pH- and lysosomal enzyme-dependent release of gemcitabine, preventing the drug from enzymatic degradation. Systemic administrations of ATF-IONP-Gem significantly inhibited the growth of orthotopic human pancreatic cancer xenografts in nude mice. With MRI contrast enhancement by IONPs, we detected the presence of IONPs in the residual tumors following the treatment, suggesting the possibility of monitoring drug delivery and assessing drug-resistant tumors by MRI. The theranostic ATF-IONP-Gem nanoparticle has great potential for the development of targeted therapeutic and imaging approaches that are capable of overcoming the tumor stromal barrier, thus enhancing the therapeutic effect of nanoparticle drugs on pancreatic cancers.

Targeted delivery of siRNA-generating DNA nanocassettes using multifunctional nanoparticles.

Molecular therapy using a small interfering RNA (siRNA) has shown promise in the development of novel therapeutics. Various formulations have been used for in vivo delivery of siRNAs. However, the stability of short double-stranded RNA molecules in the blood and efficiency of siRNA delivery into target organs or tissues following systemic administration have been the major issues that limit applications of siRNA in human patients. In this study, multifunctional siRNA delivery nanoparticles are developed that combine imaging capability of nanoparticles with urokinase plasminogen activator receptor-targeted delivery of siRNA expressing DNA nanocassettes. This theranostic nanoparticle platform consists of a nanoparticle conjugated with targeting ligands and double-stranded DNA nanocassettes containing a U6 promoter and a shRNA gene for in vivo siRNA expression. Targeted delivery and gene silencing efficiency of firefly luciferase siRNA nanogenerators are demonstrated in tumor cells and in animal tumor models. Delivery of survivin siRNA expressing nanocassettes into tumor cells induces apoptotic cell death and sensitizes cells to chemotherapy drugs. The ability of expression of siRNAs from multiple nanocassettes conjugated to a single nanoparticle following receptor-mediated internalization should enhance the therapeutic effect of the siRNA-mediated cancer therapy.

Tumor endothelial cell targeted cyclic RGD-modified heparin derivative: inhibition of angiogenesis and tumor growth.

PURPOSE: We prepared tumor endothelium targeted cRGD-modified heparin derivative (cRGD-HL) by coupling heparin-lithocholic acid (HL) with cRGDyK, and evaluated inhibition effects of cRGD-HL on angiogenesis and tumor growth. METHODS: To evaluate antiangiogenic activity of cRGD-HL, we performed tests on endothelial cell adhesion and migration to vitronectin, tube formation, binding affinity to purified alpha(v)beta(3) integrin, and in vivo Matrigel plug assay. The antitumor activity of cRGD-HL was also evaluated by monitoring tumor growth and microvessel formation in squamous cell carcinoma (SCC7) tumor. RESULTS: The cRGD-HL significantly inhibited adhesion and migration of endothelial cells to vitronectin, and tubular structures of endothelial cells. Compared to cRGDyK and HL, cRGD-HL has high binding affinity to purified alpha(v)beta(3) integrin. The enhanced antiangiogenic effect of cRGD-HL was confirmed in Matrigel assay by showing the significant inhibition of bFGF-driven angiogenesis and blood vessel formation. It was thought that potent antiangiogenic effect of cRGD-HL was probably due to the interference of alpha(v)beta(3)-mediated interaction, resulting in the enhanced antitumoral activity against SCC7 tumor. CONCLUSION: These results demonstrated that cRGD-modified heparin derivative enhanced anti-angiotherapeutic effects against solid tumor, and therefore, it could be applied to treat various cancers and angiogenic diseases as a potent angiogenesis inhibitor.

Combination therapy of heparin-deoxycholic acid conjugate and doxorubicin against squamous cell carcinoma and B16F10 melanoma.

PURPOSE: Our previous study confirmed that heparin-deoxycholic acid conjugate (HD) had a potent antiangiogenic effect and safety to use for long-term treatment. Herein, the combined therapeutic effect of HD and doxorubicin (DOX) was evaluated against squamous cell carcinoma (SCC7) and B16F10 melanoma. METHODS: The inhibitory effect of cell proliferation and cellular uptake of HD was studied in SCC7 and B16F10. The combination effects of HD and DOX were evaluated by measuring cytotoxicity and apoptosis as well as tumor growth and apoptosis in vivo against SCC7 and B16F10 tumor-bearing mice. RESULTS: HD displayed potent inhibitory effect on SCC7 and B16F10 cell proliferation, but it showed a low cytotoxic effect. Concurrent treatment of HD and DOX displayed enhanced cytotoxic effects and apoptosis on SCC7 and B16F10. The cellular uptake of HD and DOX was affected by the collective cytotoxic effects of these two drugs: each drug suppressed the tumor growth, and their combined treatment enhanced apoptosis and collectively inhibited the tumor growth of SCC7 and B16F10 in vivo. CONCLUSION: These results demonstrated that HD with cytostatic and antiangiogenetic activities, enhanced the antitumor activity of DOX against SCC7 and B16F10, and the combined treatment of these two drugs might have enhanced therapeutic efficacy.

Glucosylated heparin derivatives as non-toxic anti-cancer drugs.

Heparin, which has been widely used as an anti-coagulant agent, has potential anti-tumor effects; in particular, low molecular weight heparin (LMWH) may inhibit tumor angiogenesis and/or metastasis with reduced toxicity. For decades, it has been known that malignant cancer cells display abnormally enhanced glucose uptake rates and overexpress glucose transporters (GLUTs) compared to normal cells. With these findings in mind, we introduced a glucose moiety to heparin for the purpose of increasing the concentration of heparin at the tumor site by targeting GLUTs. Three glucosylated heparin (GH) derivatives were prepared by conjugation of glucosamine and heparin in different mole ratios. To evaluate the potential of GH derivatives as anti-cancer drugs, their anti-coagulant activities, inhibitory effects on glucose analog uptake, cellular interactions, tumor growth inhibitory effects and sub-acute toxicities were investigated. The anti-coagulant activities of GH derivatives decreased proportionally to the degree of glucosylation. In vitro, GH derivatives inhibited HUVEC proliferation to a greater extent than heparin. GH derivatives mainly existed outside of cells and interacted with GLUTs on the cell surface, thereby inhibiting glucose uptake into cells. In vivo, GH derivatives significantly suppressed tumor growth compared to control, without systemic toxicity. Therefore, GH derivatives are proposed as potent non-toxic anti-cancer drugs.

MMPs-specific PEGylated peptide-DOX conjugate micelles that can contain free doxorubicin.

The goal of this study was to develop anti-cancer drug conjugates with increased anti-tumor effect and reduced toxicity. In this regard, we utilized the physiological characteristics of tumors such as angiogenesis, the expression of matrix metalloproteinases (MMPs) and the enhanced permeability and retention (EPR) effect, and designed MMPs-specific PEGylated peptide-DOX conjugate micelles containing doxorubicin. These conjugates were prepared by using two peptides, GPLGV and GPLGVRG (P5D and P7D, respectively), and doxorubicin was loaded into micelles formed by each conjugate. P5D and P7D were specifically cleaved by active MMP-2 and all conjugates showed significantly better cell viability than doxorubicin at equivalent concentrations. In vivo, animals treated with PEGylated peptide-DOX conjugate micelles showed approximately 50% of the tumor growth of the control, and doxorubicin-loaded conjugates micelles inhibited tumor growth up to about 72% compared with the control, which matched the effect of doxorubicin. Doxorubicin-loaded PEGylated peptide-DOX conjugate micelles exhibited longer half-lives and maintained higher concentrations of doxorubicin in plasma than PEGylated peptide-DOX conjugate micelles alone. Doxorubicin-loaded PEGylated peptide-DOX conjugate micelles might offer a cancer therapy with an activity that is similar to that of the parent drug but with reduced toxicity.

Antiangiogenic and apoptotic properties of a novel amphiphilic folate-heparin-lithocholate derivative having cellular internality for cancer therapy.

PURPOSE: Anitangiogenic and apoptotic properties of a novel chemically modified heparin derivative with low anticoagulant activity were evaluated on the experimental in vitro and in vivo model. MATERIALS AND METHODS: Heparin-lithocholate conjugate (HL) was initially synthesized by covalently bonding lithocholate to heparin. Folate-HL conjugate (FHL) was further synthesized by conjugating folate to HL. Antiangiogenic and apoptotic abilities of HL and FHL were characterized in vitro and in vivo experimentations. RESULTS: Compared to unmodified heparin, both HL and FHL represented a low anticoagulant activity (38 and 28%, respectively). HL and FHL maintained antiangiogenic activity even further modification from the results of Matrigel plugs assay. FHL specifically induced apoptosis on KB cells having highly expressed folate receptor after cellular internalization. Both administered HL and FHL had similar antiangiogenic activity and inhibitory effect on tumor growth in vivo although FHL induced higher apoptosis on tumor tissues. CONCLUSIONS: In vivo tumor growth inhibition was possibly due to the decrease of vessel density and apoptotic cell death, although antiangiogenic effect of FHL seemed more actively affected on growth inhibition than apoptotic potential in vivo system. Thus, Low anticoagulant FHL having antiangiogenic and apoptotic properties would provide benefits for the development of a new class of anticancer agent.

Antiangiogenic effect of bile acid acylated heparin derivative.

PURPOSE: Chemically modified heparin-DOCA was prepared and found to have markedly lower anticoagulant activity than heparin. In the present study, we elucidated the antiangiogenic and antitumoral activities of heparin-DOCA derivative. METHODS: To evaluate the antiangiogenic and antitumoral effects of heparin-DOCA, capillary-like tube formation assay, Matrigel plug assay in vivo, western blotting for FGFR phosphorylation, ERK and p38 MAPK activities, tumor growth of SCC in vivo and immunostaining of blood vessels in tumor tissues were performed. RESULTS: Heparin-DOCA inhibited capillary-like tubular structures of endothelial cells and bFGF-induced neovascularizations in Matrigel plug assays. Signaling experiments showed that heparin-DOCA significantly inhibited angiogenesis by suppressing the phosphorylation of FGFR and its downstream signal pathways (ERK and p38 MAPK activities). The antiangiogenic activity of this heparin derivative was found to be closely associated with antitumoral activity in a mouse model. In addition, histological evaluations supported the inhibitory effect of heparin-DOCA on blood vessel formation in tumor tissues. CONCLUSION: Heparin-DOCA derivative exerted a significant antitumoral effect by inhibiting angiogenesis resulting from the disruption of FGF/FGFR and its downstream signal pathways, and could be applied to treat various angiogenic diseases.

Anti-tumor and anti-metastatic effects of gelatin-doxorubicin and PEGylated gelatin-doxorubicin nanoparticles in SCC7 bearing mice.

The goal of this study was to develop a systemically non-toxic and stable circulation based passive targeting system for efficient anticancer treatment. Gelatin-doxorubicin (GD) and PEGylated gelatin-doxorubicin (PGD) nanoparticles were designed and their feasibilities as an anti-cancer drug were evaluated. The sizes of GD and PGD nanoparticles were about 135 and 250 nm, respectively, and they retained their structures for 2 days in PBS. Both GD and PGD had much lower cytotoxicity in vitro and in vivo than doxorubicin (DOX) at equivalent concentrations. However, PGD significantly inhibited tumor growth compared to the control and DOX treated group, and GD moderately suppressed tumor growth compared with the control but the suppressing effect of GD did not exceed that of DOX. And GD and PGD both remarkably suppressed pulmonary metastasis. We conclude that PGD is a potential cancer therapeutic, due to its excellent anti-tumor and anti-metastatic effects and low systemic toxicity.

Heparin-deoxycholic acid chemical conjugate as an anticancer drug carrier and its antitumor activity.

A chemically modified heparin-DOCA (HD) conjugate was developed as a drug carrier for cancer therapy. HD conjugate was found to have markedly low anticoagulant activity and to form self-assembled nanoparticles in aqueous condition. We observed that HD conjugate prevented squamous cell carcinoma (SCC) and human umbilical vascular endothelial cell (HUVEC) proliferation during BrdU incorporation assays. Here, we prepared doxorubicin-loaded heparin nanoparticles by entrapping doxorubicin into the amphiphilic HD conjugate by physical interaction and characterized the properties of these nanoparticles using Dynamic Light Scattering (DLS) and Atomic Force Microscope (AFM). In this study, doxorubicin-loaded heparin nanoparticles were designed to improve the antitumor effects of nano-sized particles (range of 180 to 210 nm) at high drug-loading efficiencies in the range 64% to 96%. These doxorubicin-loaded heparin nanoparticles displayed sustained drug release patterns. It was confirmed in vivo toxicity studies that HD conjugate did not induce unexpected side effects and that DHN 20 was safer than free DOX. An in vivo study showed that HD conjugate, doxorubicin and DHN 20 (one of doxorubicin-loaded heparin nanoparticles) induced tumor volume reductions of 43%, 56% and 74%, respectively, relative to the saline treated control. These results suggest that the drug-entrapped with heparin nanoparticles might provide a novel therapy for SCC.