Combinational therapy: new hope for pancreatic cancer?

Pancreatic cancer is a devastating disease with a low overall survival rate. Chemotherapy is the most common treatment for patients presenting with advanced pancreatic cancer. Gemcitabine achieves a modest improvement in overall survival and is the gold standard for advanced pancreatic cancer treatment. Capecitabine and S-1, derivatives of 5-fluorouracil (5-FU), offers minimal clinical benefits. Folfirinox represents a new and aggressive regimen that might benefit patients of metastatic pancreatic cancer with good performance status. Other chemotherapy drugs such as platinums and irinotecan do not provide significant improvement in overall survival, but have been used as part of combinational therapies. Comparing to systemically delivered chemotherapy, regional intra-arterial chemotherapy achieves higher local drug concentration in tumors with lower systemic drug toxicity, and may serve as a better treatment regimen. Although there have been progress made in chemotherapeutic strategies against pancreatic cancer, the overall survival is not significantly improved in the last decade. Recently, development of chemotherapy in combination with molecular targeted therapies holds great promise in pancreatic cancer treatment, especially in patients with metastatic disease. Growing bodies of preclinical and clinical evidences indicate that the combination of conventional modalities with specific molecular targeted therapy increase the efficacy of the monotherapy without an increase in toxicity. In this review, we summarized the current regimens of chemotherapy and molecular targeted therapy for advanced pancreatic cancer and highlighted the novel combinational treatments tested in recent clinical trials.

Liposome based delivery systems in pancreatic cancer treatment: from bench to bedside

Despite rapid advances in cancer diagnosis and treatment, pancreatic cancer remains one of the most difficult human malignancies to be treated, with a mortality rate nearly equal to its incidence. Although gemcitabine has been established as the standard first-line treatment for advanced pancreatic cancer, gemcitabine-based combination chemotherapy showed either marginal or no improvement in survival. Developments in liposomal delivery systems have facilitated the targeting of specific agents for cancer treatment. Such systems could be developed as platforms for future multi-functional theranostic nanodevices tailor-made for the combined detection of early cancer and functional drug delivery. We systemically review liposome based drug-delivery systems, which can provide improved pharmacokinetics, reduced side effects and potentially increased tumor uptake, for pancreatic cancer therapy. Novel liposomal formulations allowing for higher tumor targeting efficiencies and used in current clinical trials to treat this challenging disease are emphasized.

Single-institution experience with solid pseudopapillary neoplasm of the pancreas

OBJECTIVE

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare clinical entity. The objective of this study was to review a single institution's experience with this uncommon tumor, as well as review the literature.

MATERIAL AND METHODS

Consecutive patients, who underwent surgery for a pathologically confirmed SPN between 1991 and 2010, were retrospectively reviewed. A PubMed search (January 1980-June 2011) was conducted to identify risk factors for death among SPN patients.

RESULTS

The institutional review identified 16 patients with SPN. Thirteen patients were female and three patients were male (median age 34 years). All patients underwent radical resection. Two patients had metastatic disease at the time of operation as evident by the presence of lymph node metastasis and gallbladder metastasis. One developed liver metastasis 4 months postoperatively and subsequently died. The other patient received adjuvant chemotherapy (gemcitabine and capecitabine), and 23 months after the initial operation, no tumor recurrence was detected and the patient is still alive. All other patients remain disease-free. Analysis of 29 fatalities reported in the English literature (including the present case) revealed several atypical features including male gender, old age, tumor size >5 cm, diffuse growth pattern, cellular or nuclear atypia, high mitotic rate, extensive necrosis, extrapancreatic invasion, metastasis and incomplete resection.

CONCLUSIONS

SPN is not always indolent. Male patients and those with old age, atypical histopathology (large tumors, diffuse growth, cellular/nuclear atypia, mitotic activity, necrosis, invasion/metastasis) and incomplete resection may have a higher risk of recurrence and death, deserving particular attention.

Technical tailoring of pancreaticoduodenectomy in patients with hepatic artery anatomic variants

BACKGROUND

Pancreaticoduodenectomy is the treatment of choice for periampullary and pancreatic head tumors. In case of hepatic artery abnormalities, early pancreatic transection during pancreaticoduodenectomy may prove inappropriate. Early retroportal lamina dissection improves exposure of the superior mesenteric vessels and anatomic variants of the hepatic artery, where safeguarding is mandatory.

METHOD

We describe our early retroportal lamina approach in patients with anatomic variants of the hepatic artery before pancreatic transection.

RESULTS

This approach was used during 42 pancreaticoduodenectomies with a hepatic artery anatomic variant which was spared in 40 patients. Arterial reconstruction was performed in 2 patients. Five patients with a hepatic artery variant and adenocarcinoma involving the portomesenteric junction required venous resection and reconstruction.

CONCLUSIONS

Early retroportal lamina dissection during pancreaticoduodenectomy in patients with hepatic artery anatomic variants enables easier exposure, avoiding injuries that might compromise the liver arterial supply. When the portomesenteric vein is involved, this approach facilitates en bloc "no touch" venous resection and reconstruction.

Single-walled carbon nanohorns as drug carriers: adsorption of prednisolone and anti-inflammatory effects on arthritis

Prednisolone (PSL), an anti-inflammatory glucocorticoid drug, was adsorbed on oxidized single-walled carbon nanohorns (oxSWNHs) in ethanol-water solvent. The quantity of adsorbed PSL on the oxSWNHs was 0.35-0.54 g/g depending on the sizes and numbers of holes on the oxSWNHs. PSL was adsorbed on both the outside and the inside of the oxSWNHs, and released quickly in a couple of hours and slowly within about one day from the respective places. The released quantity in culture medium strongly depended on the concentration of the PSL-oxSWNH complexes, suggesting that PSL adsorbing on oxSWNHs and PSL in the culture medium were in concentration equilibrium. The local injection of PSL-oxSWNHs into the tarsal joint of rats with collagen-induced arthritis (CIA) slightly retarded the progression of the arthritis compared with controls. By histological analysis of the ankle joint, the anti-inflammatory effect of PSL-oxSWNHs was also observed.

Magnetic nanoparticles: an update of application for drug delivery and possible toxic effects

Magnetic nanoparticles (MNPs) represent a subclass within the overall category of nanomaterials and are widely used in many applications, particularly in the biomedical sciences such as targeted delivery of drugs or genes, in magnetic resonance imaging, and in hyperthermia (treating tumors with heat). Although the potential benefits of MNPs are considerable, there is a distinct need to identify any potential toxicity associated with these MNPs. The potential of MNPs in drug delivery stems from the intrinsic properties of the magnetic core combined with their drug loading capability and the biomedical properties of MNPs generated by different surface coatings. These surface modifications alter the particokinetics and toxicity of MNPs by changing protein-MNP or cell-MNP interactions. This review contains current advances in MNPs for drug delivery and their possible organ toxicities associated with disturbance in body iron homeostasis. The importance of protein-MNP interactions and various safety considerations relating to MNP exposure are also addressed.

Development of regional chemotherapies: feasibility, safety and efficacy in clinical use and preclinical studies

Conventional oral and intravenous chemotherapies permeate throughout the body, exposing healthy tissues to similar cytotoxic drug levels as tumors. This leads to significant dose-limiting toxicities that may prevent patients from receiving sufficient treatment to overcome cancers. Therefore, a number of locoregional drug-delivery strategies have been evaluated and implemented in preclinical studies, clinical trials and in practice, in the past decades to minimize systemic toxicities from chemotherapeutic agents and to improve treatment outcomes. Localized treatment is beneficial because many cancers, such as melanoma, peritoneal cancer and breast cancer, advance locally adjacent to the site of the primary tumors prior to their circulatory invasion. In this article, we will review the feasibility, safety and efficacy of multiple localized chemotherapies in clinical use and preclinical development.

Synergistic enhancement of cancer therapy using a combination of docetaxel and photothermal ablation induced by single-walled carbon nanotubes

Background

Single-walled carbon nanotubes (SWNT) are poorly soluble in water, so their applications are limited. Therefore, aqueous solutions of SWNT, designed by noncovalent functionalization and without toxicity, are required for biomedical applications.

Methods

In this study, we conjugated docetaxel with SWNT via π-π accumulation and used a surfactant to functionalize SWNT noncovalently. The SWNT were then conjugated with docetaxel (DTX-SWNT) and linked with NGR (Asn-Gly-Arg) peptide, which targets tumor angiogenesis, to obtain a water-soluble and tumor-targeting SWNT-NGR-DTX drug delivery system.

Results

SWNT-NGR-DTX showed higher efficacy than docetaxel in suppressing tumor growth in a cultured PC3 cell line in vitro and in a murine S180 cancer model. Tumor volumes in the S180 mouse model decreased considerably under near-infrared radiation compared with the control group.

Conclusion

The SWNT-NGR-DTX drug delivery system may be promising for high treatment efficacy with minimal side effects in future cancer therapy.

Primary malignant fibrous histiocytoma: a rare case

Malignant fibrous histiocytoma (MFH) of the small intestine is an extremely rare condition. It occurs most commonly in the extremities and the trunk. We report a case of a 67-year-old woman who admitted with fever, myalgia, and altered status. After thorough investigation, a tumor of the jejunum was found. The patient underwent complete surgical removal of the tumor. A diagnosis of MFN (undifferentiated high-grade pleomorphic sarcoma) was made. The patient received adjuvant chemotherapy with Gemcitabine. Two years after the operation, the patient died due to recurrence of the disease. MFH of the small intestine is an extremely rare neoplasm with an aggressive biological behaviour. In this paper, pathogenesis, natural history, and treatment are reviewed.

Carbon nanotubes in cancer therapy and drug delivery

Carbon nanotubes (CNTs) have been introduced recently as a novel carrier system for both small and large therapeutic molecules. CNTs can be functionalized (i.e., surface engineered) with certain functional groups in order to manipulate their physical or biological properties. In addition to the ability of CNTs to act as carriers for a wide range of therapeutic molecules, their large surface area and possibility to manipulate their surfaces and physical dimensions have been exploited for use in the photothermal destruction of cancer cells. This paper paper will discuss the therapeutic applications of CNTs with a major focus on their applications for the treatment of cancer.

LyP-1-conjugated doxorubicin-loaded liposomes suppress lymphatic metastasis by inhibiting lymph node metastases and destroying tumor lymphatics

Lymphatic metastasis can be greatly promoted by metastases growth and lymphangiogenesis in lymph nodes (LNs). LyP-1, a cyclic peptide, is able to specifically bind with tumor cells and tumor lymphatics in metastatic LNs. This work aimed to use LyP-1-conjugated liposomes (L-LS) loaded with doxorubicin (DOX) (L-LS/DOX) to suppress lymphatic metastasis by inhibiting both metastases and tumor lymphatics in LNs. L-LS were prepared and exhibited sizes around 90 nm and spherical morphology as characterized by transmission electron microscopy. The in vitro cellular studies showed that LyP-1 modification obviously increased liposome uptake by MDA-MB-435 tumor cells and enhanced the cytotoxicity of liposomal DOX. A popliteal and iliac LN metastases model was successfully established by subcutaneous inoculation of tumor cells to nude mice. The immunofluorescence staining analysis indicated that LyP-1 modification enabled specific binding of liposome with tumor lymphatics and enhanced the destroying effect of liposomal DOX on tumor lymphatics. The in vivo fluorescence imaging and pharmacodynamic studies showed that LyP-1 modification increased liposome uptake by metastatic LNs and that L-LS/DOX significantly decreased metastatic LN growth and LN metastasis rate. These results suggested that L-LS/DOX were an effective delivery system for suppressing lymphatic metastasis by simultaneously inhibiting LN metastases and tumor lymphatics.

The application of carbon nanotubes in target drug delivery systems for cancer therapies

Among all cancer treatment options, chemotherapy continues to play a major role in killing free cancer cells and removing undetectable tumor micro-focuses. Although chemotherapies are successful in some cases, systemic toxicity may develop at the same time due to lack of selectivity of the drugs for cancer tissues and cells, which often leads to the failure of chemotherapies. Obviously, the therapeutic effects will be revolutionarily improved if human can deliver the anticancer drugs with high selectivity to cancer cells or cancer tissues. This selective delivery of the drugs has been called target treatment. To realize target treatment, the first step of the strategies is to build up effective target drug delivery systems. Generally speaking, such a system is often made up of the carriers and drugs, of which the carriers play the roles of target delivery. An ideal carrier for target drug delivery systems should have three pre-requisites for their functions: (1) they themselves have target effects; (2) they have sufficiently strong adsorptive effects for anticancer drugs to ensure they can transport the drugs to the effect-relevant sites; and (3) they can release the drugs from them in the effect-relevant sites, and only in this way can the treatment effects develop. The transporting capabilities of carbon nanotubes combined with appropriate surface modifications and their unique physicochemical properties show great promise to meet the three pre-requisites. Here, we review the progress in the study on the application of carbon nanotubes as target carriers in drug delivery systems for cancer therapies.

Dual targeted delivery of doxorubicin to cancer cells using folate-conjugated magnetic multi-walled carbon nanotubes

By combining the advantage of multi-walled carbon nanotubes (MWCNTs) and iron oxide magnetic nanoparticles (MNs), we develop a magnetic dual-targeted nanocarrier for drug delivery. MWCNTs were functionalized with poly(acrylic acid) through free radical polymerization, decorated with MNs, conjugated with a targeting ligand folic acid (FA), for loading of an anti-cancer drug doxorubicin (DOX). The proposed methodology provides dual targeted delivery of the anti-cancer drug to cancer cells under the guidance of a magnetic field and through ligand-receptor interactions. The chemico-physical properties of the nanocarrier were characterized, in addition to its drug loading efficiency and drug releasing characteristics. Doxorubicin could be loaded to MWCNTs with high efficiency via π-π stacking and hydrogen bonding and showed enhanced cytotoxicity toward U87 human glioblastoma cells compared with free DOX. From transmission electron microscopy and confocal laser scanning microscopy, we confirmed that DOX-FA-MN-MWCNT could be efficiently taken up by U87 cells with subsequent intracellular release of DOX, followed by transport of DOX into the nucleus with the nanocarrier left in the cytoplasm. These properties make the magnetic nanocarrier a potential candidate for targeted delivery of DOX for cancer treatment.

Laparoscopy-assisted resection for Mesenteric Castleman's disease: Report of a case

A 65-year-old female patient was diagnosed with breast cancer in 1995. An abdominal mass was detected by computed tomography and the patient was preoperatively diagnosed with a gastrointestinal stromal tumor. Laparoscopy-assisted surgical resection revealed a mesenteric Castleman's tumor of the hyaline vascular type. Mesenteric Castleman's disease is rare, and there have been only 42 cases reported in the English literature. We herein discuss the clinical findings of these cases.

Formulation and evaluation of celastrol-loaded liposomes

The main purpose of this study was to evaluate the intestinal absorption and the antineoplastic effect of the poorly water-soluble drug celastrol when liposomes were used as oral drug delivery system. Liposomes were prepared by the ethanol-injection method. An optimized liposome formulation composed of phospholipid, cholesterol and Tween-80 resulted in favorable encapsulation efficiency at 98.06 ± 0.94%. Homogeneous and stable particle size of 89.6 ± 7.3 nm and zeta potential of -(87.7 ± 5.8) mV were determined by laser particle size analyzer. Subsequently, the four-site perfusion rat intestinal model revealed that celastrol-loaded liposomes had improved effective permeability compared to the free drug in four intestinal segments (p < 0.05). Moreover, celastrol-loaded liposomes could also inhibit the tumor growth in C57BL/6 mice. These results suggest that liposomes could be a promising perioral carrier for celastrol.

Advances in lymphatic imaging and drug delivery

Cancer remains the second leading cause of death after heart disease in the US. While metastasized cancers such as breast, prostate, and colon are incurable, before their distant spread, these diseases have invaded the lymphatic system as a first step in their progression. Hence, proper evaluation of the disease state of the lymphatics which drain a tumor site is crucial to staging and the formation of a treatment plan. Current lymphatic imaging modalities with visible dyes and radionucleotide tracers offer limited sensitivity and poor resolution; however, newer tools using nanocarriers, quantum dots, and magnetic resonance imaging promise to vastly improve the staging of lymphatic spread without needless biopsies. Concurrent with the improvement of lymphatic imaging agents, has been the development of drug carriers that can localize chemotherapy to the lymphatic system, thus improving the treatment of localized disease while minimizing the exposure of healthy organs to cytotoxic drugs. This review will focus on the use of various nanoparticulate and polymeric systems that have been developed for imaging and drug delivery to the lymph system, how these new devices improve upon current technologies, and where further improvement is needed.

Magnetic functionalised carbon nanotubes as drug vehicles for cancer lymph node metastasis treatment

Strategies using carbon-based nanomaterials as carriers for delivering chemotherapeutic drugs to cancers have been described well. Here a novel magnetic lymphatic-targeting drug-delivery system, based on functionalised carbon nanotubes (fCNTs), is presented with the aim of improving the outcome of cancer with lymph node involvement. The potential therapeutic effect of gemcitabine (GEM) loading magnetic multiwalled carbon nanotubes (mMWNTs) was compared with that of GEM loading magnetic-activated carbon particles (mACs) in vitro and in vivo. mMWNTs-GEM and mACs-GEM both had high anti-tumour activity in vitro similar to free drug. Subcutaneous administration of GEM loading magnetic nanoparticles resulted in successful regression and inhibition of lymph node metastasis under the magnetic field, with mMWNTs-GEM superior to mACs-GEM, and more effectively in the high-dose versus low-dose groups. The successful application of intra-lymphatic delivery of chemotherapeutics using mMWNTs highlights the clinical potential of fCNTs for future cancer metastasis treatment with high efficacy and minimum side-effects.

Effect of cocoa-enriched diets on lymphocytes involved in adjuvant arthritis in rats

Cocoa and its flavonoids have potential anti-inflammatory properties in vitro and in acute inflammation models in vivo. The aim of the present study was to ascertain the effects of two cocoa-enriched diets on adjuvant arthritis (AA) in rats, considering not only clinical and biochemical inflammatory indices, but also antibody response and lymphocyte composition. Female Wistar rats were fed with a 5 or 10 % cocoa-enriched diet beginning 2 weeks before arthritis induction and until the end of the study. AA was induced by an intradermal injection of heat-killed Mycobacterium butyricum suspension. The hind-paw swelling (plethysmometry), serum anti-mycobacterial antibody concentration (ELISA), blood and inguinal lymph node lymphocyte subset percentage (flow cytometry), and IL-2, interferon γ and PGE₂ released from splenocytes (ELISA) were assessed. Although the cocoa diets had no significant effect on hind-paw swelling, a tendency to reduce it was observed at the end of the study. Cocoa-enriched diets were able to decrease the serum anti-mycobacterial antibody concentration and the splenocyte PGE2 production, as well as the proportion of T-helper (Th) lymphocytes in blood and regional lymph nodes, which probably includes cells responsible for the arthritic process. The cocoa diets prevented a decrease in the proportion of regulatory T-cells in blood and a disequilibrium between inguinal lymph node natural killer (NK) CD8⁺ and NK CD8⁻ subsets. In conclusion, the cocoa-enriched diets during AA were not able to significantly decrease joint inflammation but modified Th-cell proportions and prevented specific antibody synthesis.

Overcoming drug resistance in pancreatic cancer

INTRODUCTION

Pancreatic cancer has the worst survival rate of all cancers. The current standard care for metastatic pancreatic cancer is gemcitabine, however, the success of this treatment is poor and overall survival has not improved for decades. Drug resistance (both intrinsic and acquired) is thought to be a major reason for the limited benefit of most pancreatic cancer therapies.

AREAS COVERED

Previous studies have indicated various mechanisms of drug resistance in pancreatic cancer, including changes in individual genes or signaling pathways, the influence of the tumor microenvironment, and the presence of highly resistant stem cells. This review summarizes recent advances in the mechanisms of drug resistance in pancreatic cancer and potential strategies to overcome this.

EXPERT OPINION

Increasing drug delivery efficiency and decreasing drug resistance is the current aim in pancreatic cancer treatment, and will also benefit the treatment of other cancers. Understanding the molecular and cellular basis of drug resistance in pancreatic cancer will lead to the development of novel therapeutic strategies with the potential to sensitize pancreatic cancer to chemotherapy, and to increase the efficacy of current treatments in a wide variety of human cancers.

Review on the progress in synthesis and application of magnetic carbon nanocomposites

This review focuses on the synthesis and application of nanostructured composites containing magnetic nanostructures and carbon-based materials. Great progress in fabrication of magnetic carbon nanocomposites has been made by developing methods including filling process, template-based synthesis, chemical vapor deposition, hydrothermal/solvothermal method, pyrolysis procedure, sol-gel process, detonation induced reaction, self-assembly method, etc. The applications of magnetic carbon nanocomposites expanded to a wide range of fields such as environmental treatment, microwave absorption, magnetic recording media, electrochemical sensor, catalysis, separation/recognization of biomolecules and drug delivery are discussed. Finally, some future trends and perspectives in this research area are outlined.

Immunohistochemical evaluation of solid pseudopapillary tumors of the pancreas: the expression pattern of CD99 is highly unique

The aim of this study was to investigate CD99 as a new marker to characterize solid pseudopapillary tumors (SPTs), and to determine a specific panel of markers to identify the disease. We analyzed the clinicopathological characteristics and immunohistochemical features of 37 patients with SPT. All 37 tumors displayed intracytoplasmic dot-like immunoreactivity of CD99 in contrast to membranous staining in all pancreatic endocrine tumors and most of acinar cell carcinomas, along with negative immunostaining in ductal carcinomas. In addition, we observed a loss of expression of E-cadherin in all SPTs as well as in some other pancreatic tumors, and aberrant nuclear expression of β-catenin in most SPTs. Our findings demonstrated for the first time that the pattern of CD99 expression was highly specific for distinguishing SPTs from other pancreatic tumors. CD99 combined with E-cadherin/β-catenin and CD10 can be used as a relatively specific expression profile of SPTs.

Solid pseudopapillary tumor of the pancreas: can malignancy be predicted?

BACKGROUND

The objective of this study was to examine the clinicopathologic characteristics of solid pseudopapillary tumors (SPTs) of the pancreas, including the risk factors for disease recurrence and their effects on survival.

METHODS

The medical records of 114 patients who underwent surgery for a pathologically confirmed SPT between January 1995 and December 2007 were reviewed retrospectively.

RESULTS

Of the 114 patients, 98 (86.9%) were female, and the median age was 36 years (range, 11-75). All 114 patients underwent curative intent surgery and 13 (11.4%) underwent laparoscopic surgery. Of the 114 patients, 26 (22.8%) had solid pseudopapillary carcinoma (SPC). There were no differences in any clinical factors between the benign SPT and SPC groups; however, the only 4 recurrences identified were in the SPC group. After follow-up ranging from 11 to 177 months, all 114 patients were alive, with only 4 showing evidence of recurrence. Recurrence was observed in young patients with metastasis at first operation, invasion of an adjacent organ, and a large mass (≥13 cm).

CONCLUSION

Adequate operative resection including laparoscopic surgery is the mainstay of treatment for SPT. Although statistically significant risk factors for recurrence cannot be determined, tumor metastasis at the first operation, invasion of adjacent organ, large tumor size, young patient age, tumor rupture, and inadequate resection may increase the risk of recurrence. Our results demonstrate that long-term survival could be achieved by aggressive operative resection and interventional treatment of recurrent disease.

Effects of an Engineered Anti-HER2 Antibody chA21 on Invasion of Human Ovarian Carcinoma Cell In Vitro

OBJECTIVE

HER-2 plays an important role in the development and progression of ovarian carcinoma. A number of monoclonal antibodies (MAbs) and engineered antibody fragments (such as scFvs) against the subdomain II or IV of HER-2 extracellular domain (ECD) have been developed. We investigated the effect of chA21, an engineered anti-HER-2 antibody that bind primarily to subdomain I, on ovarian carcinoma cell invasion in vitro, and explored its possible mechanisms.

METHODS

Growth inhibition of SK-OV-3 cells was assessed using a Methyl thiazolyl tetrazolium (MTT) assay. The invasion ability of SK-OV-3 was determined by a Transwell invasion assay. The expression of matrix metalloproteinase-2 (MMP-2) and its tissue inhibitors (TIMP-2) was detected by immunocytochemical staining, and the expression of p38 and the phosphorylation of p38 were assayed by both immunocytochemistry and Western blot.

RESULTS

After treatment with chA21, the invasion of human ovarian cancer SK-OV-3 cells was inhibited in dose- and time-dependent manners. Simultaneously the expression of p38, phospho-p38, MMP-2 and the MMP-2/TIMP-2 ratio decreased, while TIMP-2 expression increased. Additionally, the decrease in phospho-p38 was much greater than that of p38.

CONCLUSION

chA21 may inhibit SK-OV-3 cell invasion via the signal transduction pathway involving MMP-2, TIMP-2, p38 and the activation of p38MAPK.

Research progress on siRNA delivery with nonviral carriers

RNA interference is a powerful method for the knockdown of pathologically relevant genes. Small interfering RNAs (siRNAs) have been widely demonstrated as effective biomedical genetic-therapy applications for many diseases. Unfortunately, siRNA duplexes are not ideal drug-like molecules. Problems hindering their effective application fundamentally lie in their delivery, stability, and off-target effects. Delivery systems provide solutions to many of the challenges facing siRNA therapeutics. Due to some fatal disadvantages of viral vectors, nonviral carriers have been studied extensively. Aside from liposomes, nanoparticles and cationic polymer carriers have exhibited improved in vivo stability, better biocompatibility, and efficiency for gene silencing with less cellular toxicity. They may represent a promising strategy for siRNA-based therapies, especially as nanomaterials. The present review also summarizes other methods of siRNA delivery and the side effects of the nanoparticles.

Therapeutic ultrasonic microbubbles carrying paclitaxel and LyP-1 peptide: preparation, characterization and application to ultrasound-assisted chemotherapy in breast cancer cells

The aim of this work was to develop a novel targeted drug-loaded microbubble (MB) and to investigate its chemotherapy effect in vitro. Paclitaxel (PTX)-loaded lipid MBs were prepared by a mechanical vibration technique. The LyP-1, a breast tumor homing peptide, was coated onto the surface of PTX-loaded MBs through biotin-avidin linkage. The resulting targeted drug-loaded MBs were characterized and applied to ultrasound-assisted chemotherapy in breast cancer cells. Our results showed the ultrasonic MBs were able to achieve 43%-63% of drug encapsulation efficiency, depending on drug loading amount. The binding affinity assay indicated the attachment of targeted MBs to human MDA-MB-231 breast cancer cells was highly efficient and stable even with ultrasonic irradiation on. The cellular uptake efficiency of payload in targeted MBs was 3.71-, 4.95-, 7.43- and 7.66-fold higher than that of non-targeted MBs at the applied ultrasound time of 30, 60, 90 and 120 s, respectively. In addition, the cell proliferation inhibition assay showed the cell viability of targeted PTX-loaded MBs was significantly lower than that of non-targeted PTX-loaded MBs and non-targeted unloaded MBs when ultrasound was utilized. In conclusion, the study indicated the LyP-1-coated PTX-loaded MBs significantly increased the antitumor efficacy and can be used as a potential chemotherapy approach for ultrasound-assisted breast cancer treatment.

Nanotechnology and drug delivery: an update in oncology

The field of nanotechnology has exploded in recent years with diverse arrays of applications. Cancer therapeutics have recently seen benefit from nanotechnology with the approval of some early nanoscale drug delivery systems. A diversity of novel delivery systems are currently under investigation and an array of newly developed, customized particles have reached clinical application. Drug delivery systems have traditionally relied on passive targeting via increased vascular permeability of malignant tissue, known as the enhanced permeability and retention effect (EPR). More recently, there has been an increased use of active targeting by incorporating cell specific ligands such as monoclonal antibodies, lectins, and growth factor receptors. This customizable approach has raised the possibility of drug delivery systems capable of multiple, simultaneous functions, including applications in diagnostics, imaging, and therapy which is paving the way to improved early detection methods, more effective therapy, and better survivorship for cancer patients.

Dispersion stability and exothermic properties of DNA-functionalized single-walled carbon nanotubes

Carbon nanotubes act as a photon antenna that serves as an effective "molecular heater" around the near-infrared (NIR) region. This exothermic generation can be used as a possible heating source for hyperthermia therapy. The current study reports the dispersible and exothermic properties with NIR irradiation for single-walled carbon nanotubes (SWNTs) treated with a strong acid (acid-treated SWNTs), and the SWNTs further functionalized with double-stranded DNA (DNA-functionalized SWNTs: DNA-SWNTs). DNA-SWNTs significantly improved the dispersibility of SWNTs when compared with the acid-treated SWNTs. The binding ratio of the acid-treated SWNT and DNA was calculated to be 3.1 (DNA/SWNTs) from the phosphorous content in the DNA-SWNT. This interaction of the SWNTs and DNA would contribute to the stable dispersion of the DNA-SWNTs in a culture medium. With NIR irradiation by a halogen lamp light source, the acid-treated SWNTs and the DNA-SWNTs showed strong heat evolution in vitro (in a culture medium) and in vivo (in the subcutaneous tissue of a mouse) condition without any invasive effect on the non-SWNT area. The results of this study suggested that the functionalization with DNA was an efficient approach to improve the dispersibility of SWNTs in body fluids, and the DNA-SWNT would be a promising source for photo-induced exothermic generation.

Malignant fibrous histiocytoma of rectum: Report of a case

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma of adults, mostly distributed in the thigh, buttock and groin (46%) and presents rarely in the gastrointestinal tract, classified as gastrointestinal stromal tumors (GIST). MFH is regarded as a diagnosis of exclusion, essentially synonymous with an undifferentiated pleomorphic sarcoma. The recent report presents an 80-year-old man with clinical manifestations of rectal bleeding and final diagnosis of MFH of rectum. It seems that radical resection and adjuvant radiation is important in the management strategy of a patient with such a rare rectal tumor.

Recent advances of siRNA delivery by nanoparticles

INTRODUCTION

The field of RNA interference technology has been researched extensively in recent years. However, the development of clinically suitable, safe and effective drug delivery vehicles is still required.

AREAS COVERED

This paper reviews the recent advances of non-viral delivery of small interfering RNA (siRNA) by nanoparticles, including biodegradable nanoparticles, liposomes, polyplex, lipoplex and dendrimers. The characteristics, composition, preparation, applications and advantages of different nanoparticle delivery strategies are also discussed in detail, along with the recent progress of non-viral nanoparticle carrier systems for siRNA delivery in preclinical and clinical studies.

EXPERT OPINION

Non-viral carrier systems, especially nanoparticles, have been investigated extensively for siRNA delivery, and may be utilized in clinical applications in the future. So far, a few preliminary clinical trials of nanoparticles have produced promising results. However, further research is still required to pave the way to successful clinical applications. The most important issues that need to be focused on include encapsulation efficiency, formulation stability of siRNA, degradation in circulation, endosomal escape and delivery efficiency, targeting, toxicity and off-target effects. Pharmacology and pharmacokinetic studies also present another great challenge for nanoparticle delivery systems, owing to the unique nature of siRNA oligonucleotides compared with small molecules.

Endoscopic ultrasound in the assessment of solid and cystic pancreatic lesions

Pancreatic masses can be solid or cystic, benign or malignant. Rapid and accurate diagnosis is essential for optimal management. Clinical presentation and radiological appearance are often inadequate for a definitive diagnosis. Endoscopic ultrasound allows more detailed assessment of the pancreas than traditional imaging techniques.

In vivo activity of novel anti-ErbB2 antibody chA21 alone and with Paclitaxel or Trastuzumab in breast and ovarian cancer xenograft models

It was well studied that ErbB2 (HER2/p185(her2/neu)) overexpression in human malignant cancers correlates with poor prognosis and chemo-resistance. Although Trastuzumab (Herceptin) has been widely used in patients with ErbB2-overexpressing metastatic breast cancer, many patients either do not respond to Trastuzumab therapy or progress within 1 year of initiating Trastuzumab treatment. Previously, we reported a novel tumor-inhibitory antibody chA21, which recognized ErbB2 extracellular domain with an epitope distinct from other tumor-inhibitory anti-ErbB2 antibodies. Here, we report that chA21 combined with Paclitaxel or Trastuzumab significantly enhances the tumor-inhibition effects on ErbB2-overexpressing breast and ovarian cancer in xenograft mice. Moreover, the study reveals that the effects by chA21 to cause an enhanced inhibition on cancer cell proliferation and angiogenesis was highly associated with the intrinsic ability of chA21 to down-regulate ErbB2 receptor, inhibit downstream MAPK and PI3K-AKT signal transduction and activate natural killer cells. Our findings show that chA21 may represent a unique anti-ErbB2 antibody with potentials as therapeutic candidate alone or combination with other anti-ErbB2 reagents in cancer therapy.

Primary intra-abdominal malignant fibrous histiocytoma: a highly aggressive tumor

BACKGROUND AND PURPOSE

Malignant fibrous histiocytoma (MFH) is the most common soft-tissue sarcoma of late adult life occurring predominantly in the extremities. Primary intra-abdominal MFH is a very rare occurrence. The aim of this study is to describe a very rare case of an intra-abdominal MFH with a highly aggressive clinical course.

METHODS

A 67-year-old male was referred to our department with a 2-week history of dull lower abdominal pain and a gradually enlarging right lower abdominal mass, which he first noticed 2 months prior to admission. Computed tomography (CT) scan demonstrated a mass in the right iliac fossa.

RESULTS

On exploratory laparotomy, a tumor was found in the right iliac fossa attached to the parietal lateral peritoneum without any evidence of invasion into the adjacent structures. Complete excision of the tumor with clear margins was performed. Histological and immunohistochemical examinations showed a MFH. One month after surgery, while on adjuvant chemotherapy, the patient was readmitted with dyspnea and a slightly palpable mass in the area of the previous radical resection. CT scan revealed local tumor recurrence along with multiple pulmonary metastatic deposits. Unfortunately, despite treatment, the patient died of progressive disease 5 weeks later.

CONCLUSIONS

Primary intra-abdominal MFH is a very rare but aggressive malignancy with a high tendency of local recurrence and metastatic spread. Early detection and complete surgical excision with clear margins is the treatment of choice. In some cases, however, the tumor can exhibit a highly aggressive clinical course despite radical surgery and adjuvant therapy.

Solid pseudopapillary tumors of the pancreas. Clinical features, surgical outcomes, and long-term survival in 45 consecutive patients from a single center

BACKGROUND

Solid pseudopapillary tumors of the pancreas (SPT) are rare neoplasms, and the natural history is poorly defined. The aim of this study was to define the natural history and compare patient and tumor factors between patients with malignant and non-malignant disease.

METHODS

Data for all patients with SPT who underwent surgical exploration at MSKCC between 1987 and 2009 were collected and analyzed. Patient, tumor, treatment, and survival variables were examined. Malignant tumors were defined as any tumor that was locally unresectable, metastatic, or recurrent. Differences between groups were analyzed by Fisher's exact, chi-squared, Wilcoxon, and log-rank tests.

RESULTS

Forty-five patients had an SPT during the study period. Median age was 38 years (10-63) and 38 (84%) were women. At the time of diagnosis, 38 were symptomatic, with the most common symptom being abdominal pain (n = 35). The most frequent imaging characteristic was a solid and cystic tumor (n = 29), most commonly located in the tail of the pancreas (n = 23). Resection of the primary tumor (n = 41) (41/2,919 = 1.4% of all resections) included distal pancreatectomy in 26, pancreatoduodenectomy in 11, central pancreatectomy in two, and enucleation in two. Nine patients had malignant disease defined by a locally unresectable tumor in three, liver metastases in three, locally unresectable tumor and liver metastases in one, local recurrence and liver metastases in one, and local recurrence in another. Patients with malignant disease presented with larger tumors (7.8 vs. 4.2 cm) (p < 0.005). After median follow-up of 44 months, 34 patients were without evidence of disease, four patients were alive with disease, three patients died of disease, and four patients died of other causes.

CONCLUSIONS

These results demonstrate that SPT occurs in young women, and the majority of patients will experience long-term survival following resection. The only feature associated with malignant disease was tumor size at presentation. The majority of patients are alive at last follow-up, and a low percentage experienced disease recurrence or death from disease.

Efficient synthesis of tailored magnetic carbon nanotubes via a noncovalent chemical route

We report here an efficient noncovalent chemical route to dense and uniform assembly of magnetic nanoparticles onto multi-walled carbon nanotubes within a single-layer configuration. While preserving the electrical conduction behavior of the nanotube network itself, the resulting carbon nanotube derivatives exhibit a distinct superparamagnetism, and can be magnetically manipulated via a quick and reversible mode.

How to manage a patient with multiple adenomatous polyps

Adenomatous polyps are found on screening colonoscopy in 22.5% to 58.2% of the adult population and therefore represent a common problem. Patients with multiple adenomatous polyps are of unique interest because a proportion of these patients have an inheritable form of colorectal cancer. This article discusses the history and clinical features, genetic testing, surveillance, and treatments for the condition.

MR imaging features of small solid pseudopapillary tumors: retrospective differentiation from other small solid pancreatic tumors

OBJECTIVE

The purpose of this study was to describe the MRI features of small solid pseudopapillary tumors useful for differentiating these tumors from other small solid pancreatic tumors.

MATERIALS AND METHODS

Forty-five patients (18 men, 27 women; mean age, 59 ± 11.7 years) with 45 solid pancreatic tumors smaller than 3 cm in diameter registered from 2000 to 2009 were included. Twenty-two of the tumors were adenocarcinomas, 12 were endocrine tumors, and 11 were solid pseudopapillary tumors. Two radiologists analyzed the MR images for morphologic features, signal intensity of the lesion on unenhanced images, and dynamic enhancement pattern. The contrast-to-noise ratio between the lesion and the pancreas was calculated on T1- and T2-weighted images and on dynamic images.

RESULTS

Solid pseudopapillary tumors commonly had the following features: completely well-defined margin (82%), pure solid consistency (82%), low signal intensity on unenhanced T1-weighted images (100%), high signal intensity on T2-weighted images (100%), a strong predominance among women (91%), and early heterogeneous and slowly progressive enhancement (100%). The solid pseudopapillary tumors rarely had a capsule or hemorrhage. A characteristic qualitative feature of solid pseudopapillary tumors that was significantly different from the other two tumor types was very high signal intensity on T2-weighted images (p < 0.01). Quantitative analysis showed that the solid pseudopapillary tumors had a lower contrast-to-noise ratio (-16.82 ± 5.84) on T1-weighted images and a higher contrast-to-noise ratio (37.35 ± 33.59) on T2-weighted images than did the other two tumor types (p < 0.01).

CONCLUSION

Small solid pseudopapillary tumors were predominantly seen as completely well-demarcated pure solid tumors in middle-aged women. They had lower signal intensity on T1-weighted images and higher signal intensity on T2-weighted images than did the other two tumor types and had early heterogeneous and progressive enhancement.

Role of endoscopic ultrasound for evaluating gastrointestinal tract disorders in pediatrics: a tertiary care center experience

BACKGROUND

Endoscopic ultrasound (EUS) with or without fine needle aspiration (FNA) has a well-established role in the evaluation of various gastrointestinal (GI) tract disorders in adults. The clinical impact of EUS on the management of the pediatric population remains less clear. This study evaluates the feasibility, safety, and applications of EUS ± FNA in pediatric GI tract disorders.

PATIENTS AND METHODS

Using a prospectively maintained EUS database, all patients 18 years of age or younger referred for EUS at our institution were identified. Retrospective chart review was conducted to document procedure indications, type of anesthesia used, EUS findings, final FNA cytology results, and clinical impact of EUS ± FNA on the subsequent management of pediatric patients.

RESULTS

Fifty-eight EUS procedures were performed in 56 patients (35 girls). Median age was 16 years (range 4-18 years). The main indications for EUS were acute or recurrent pancreatitis, abdominal pain of suspected pancreatobiliary origin, suspected biliary obstruction, upper GI mucosal/submucosal lesions, and evaluation of pancreatic abnormalities seen on prior imaging. Sedation used included nurse-administered propofol sedation in 38 (73%), general anesthesia in 9 (17%), and fentanyl with meperidine in 3 (6%). Five therapeutic procedures performed included celiac plexus blocks in 4 and 1 EUS-guided pancreatogram. In 44 (86%) patients, EUS provided a new diagnosis. The procedure was successfully completed in all patients with no reported complications.

CONCLUSIONS

EUS ± FNA is feasible and safe and makes a significant impact on most pediatric patients. Nurse-administered propofol sedation appears to be safe and well tolerated in this group.

Advancement in carbon nanotubes: basics, biomedical applications and toxicity

Objectives

Carbon nanotubes (CNTs) have attracted much attention by researchers worldwide in recent years for their small dimensions and unique architecture, and for having immense potential in nanomedicine as biocompatible and supportive substrates, as a novel tool for the delivery of therapeutic molecules including peptides, RNA and DNA, and also as sensors, actuators and composites.

Key findings

CNTs have been employed in the development of molecular electronic, composite materials and others due to their unique atomic structure, high surface area-to-volume ratio and excellent electronic, mechanical and thermal properties. Recently they have been exploited as novel nanocarriers in drug delivery systems and biomedical applications. Their larger inner volume as compared with the dimensions of the tube and easy immobilization of their outer surface with biocompatible materials make CNTs a superior nanomaterial for drug delivery. Literature reveals that CNTs are versatile carriers for controlled and targeted drug delivery, especially for cancer cells, because of their cell membrane penetrability.

Summary

This review enlightens the biomedical application of CNTs with special emphasis on utilization in controlled and targeted drug delivery, as a diagnostics tool and other possible uses in therapeutic systems. The review also focuses on the toxicity aspects of CNTs, and revealed that genotoxic potential, mutagenic and carcinogenic effects of different types of CNTs must be explored and overcome by formulating safe biomaterial for drug delivery. The review also describes the regulatory aspects and clinical and market status of CNTs.

Carbon nanotubes in cancer theragnosis

Carbon nanotubes as a unique and novel class of nanomaterials have shown considerable promise in cancer therapy and diagnosis amidst the myriad of nanocarriers. The presence of a large surface area enables the engineering of the surface of nanotubes, thus making them biocompatible, and large benefits can be harnessed from them. Together with their ability to encapsulate small molecules, stacking interactions and conjugation, nanotubes have improved the profile of anticancer agents. The propensity to absorb the body transparent NIR radiation also envisages photothermal and photoacoustic therapy using nanotubes. This article sheds light on the role of carbon nanotubes in cancer therapy and diagnosis based on recent findings.

Clinical strategy for the management of solid pseudopapillary tumor of the pancreas: aggressive or less?

OBJECTIVE

To further delineate the clinicopathological and radiological features of solid pseudopapillary tumor (SPT) of the pancreas and summarize the surgical therapy strategy for this tumor.

METHODS

A retrospective review of 18 pathologically confirmed cases of SPT was performed and the clinical and pathological features, radiological findings and surgical interventions were analyzed.

RESULTS

The patients included 17 females and 1 male with a median age of 23 years. The median diameter of the lesions was 8.0 cm. Abdominal pain was the predominant complaint (8/18). The rest of the patients were asymptomatic and presented with a pancreatic mass detected incidentally. Radiological study revealed a well-demarcated mass which was composed of a solid-cystic portion. On post-contrast CT, the solid portions could be enhanced whereas the cystic parts remained unenhanced. With the preoperative diagnosis of SPT in 11 patients and pancreatic cyst, benign or malignant pancreatic tumor in the rest, pancreatic tumor resection was successfully completed. Surgical exploration findings, pathological characteristics and good prognosis of the patients with SPT, indicated its low-grade malignant potential.

CONCLUSION

In combination with clinical findings, radiological features of SPT may help to make the correct diagnosis and differentiation from other pancreatic neoplasms. Once diagnosed, given the excellent prognosis and low-grade malignancy, less aggressive surgical resection of the primary lesion is proposed.

Augmented inhibition of angiogenesis by combination of HER2 antibody chA21 and trastuzumab in human ovarian carcinoma xenograft

Background

chA21 is a novel tumor-inhibitory antibody which recognized subdomain I of HER2 extracellular domain with an epitope distinct from other HER2 antibodies. Previously, we demonstrated that chA21 inhibits human ovarian carcinoma cell line SKOV-3 growth in vitro and in vivo study. In this study, we further investigated the anti-angiogenic efficacy combination of chA21 with trastuzumab in SKOV-3 xenograft model.

Methods

Nude mice were s.c. challenged with SKOV-3 cells and received treatment of chA21 alone, trastuzumab alone or both antibodies together twice a week for 21 days. Tumor volume and microvessel density (MVD) were evaluated. The effect of chA21 plus trastuzumab treament on vascular endothelial growth factor (VEGF) secretion, endothelial cells proliferation and migration, and the status of HER2 downstream pathway AKT/phosphorylated AKT (pAKT) were evaluated in vitro.

Results

In vivo study combination of chA21 with trastuzumab resulted in reduce tumor growth and angiogenesis than each monotherapy. In vitro study, the combination of chA21 with trastuzumab inhibits VEGF secretion, endothelial cells proliferation and migration. Furthermore, the combination treatment inhibits pAKT expression.

Conclusion

Our findings suggested that the combination of chA21 with trastuzumab can cause augmented inhibition of angiogenesis in SKOV-3 xenograft model. Inhibition of agniogenesis may through suppression of AKT pathway. The therapeutic benefits of combination chA21 with trastuzumab warrant further study in an attempt to make the translation into the clinic.

Carbon nanotubes in cancer diagnosis and therapy

During the past years, great progress has been made in the field of nanomaterials given their great potential in biomedical applications. Carbon nanotubes (CNTs), due to their unique physicochemical properties, have become a popular tool in cancer diagnosis and therapy. They are considered one of the most promising nanomaterials with the capability of both detecting the cancerous cells and delivering drugs or small therapeutic molecules to these cells. Over the last several years, CNTs have been explored in almost every single cancer treatment modality, including drug delivery, lymphatic targeted chemotherapy, thermal therapy, photodynamic therapy, and gene therapy. In this review, we will show how they have been introduced into the diagnosis and treatment of cancer. Novel SWNT-based tumor-targeted drug delivery systems (DDS) will be highlighted. Furthermore, the in vitro and in vivo toxicity of CNTs reported in recent years will be summarized.

Homing peptides as targeted delivery vehicles

Each normal organ and pathological condition appear to contain organ- or disease-specific molecular tags on its vasculature, which constitute a vascular "zip code" system. In vivo phage display has been exploited to profile this vascular heterogeneity and a number of peptides that home specifically to various normal organs or pathological conditions have been identified. These peptides have been used for targeted delivery of oligonucleotides, drugs, imaging agents, inorganic nanoparticles, liposomes, and viruses. Identification of the receptor molecules for the homing peptides has revealed novel biomarkers for target organs. In tumors many of these receptors seem to play a functional role in tumor angiogenesis. Recently, tumor homing peptides have entered clinical trials. Results from several Phase I and II trials have been reported, and a number of trials are currently ongoing or recruiting patients. In these trials no dose-limiting toxicity has occurred and all combinations of peptide-targeted therapies have been well tolerated.

Efficient overcoming of drug resistance to anticancer nucleoside analogs by nanodelivery of active phosphorylated drugs

One of the major problems in cancer chemotherapy is the fast development of drug resistance to most anticancer therapeutics. Thus, an important cause of the eventual decline in clinical efficacy of cytotoxic nucleoside analogs was the selection of resistant cancer cells with deficiencies in the expression of nucleoside transporters or nucleoside-activating kinases. Here, we present an efficient strategy of overcoming this type of drug resistance by tumor-specific delivery of nanogel-encapsulated active triphosphates of nucleoside analogs (NATP). The small particles of biodegradable cationic nanogels loaded with anionic NATP efficiently interacted with cancer cells and released active drug compounds into the cytoplasm. The potential of novel drug formulations was evaluated in the nucleoside transport-deficient (CEM/araC/C8) or nucleoside activation-deficient (RL7/G) lymphogenic cancer cells. Compared to nucleoside analogs, NATP-loaded nanogels demonstrated increased cytotoxicity, reducing the drug resistance index 250- to 900-fold in CEM/araC/C8 cells and 70- to 100-fold in RL7/G cells. The strong cytotoxic effect of nanoformulations was accompanied by characteristic cell cycle perturbations, usually observed in drug-treated sensitive cells, and resulted in the induction of apoptosis in all studied drug-resistant cells. Efficient cellular accumulation of nanogels and the consequent increase in intracellular levels of NATP were found to be the major factors determining cytotoxic efficacy of nanoformulations. Decoration of nanogels with multiple molecules of tumor lymphatic-specific peptide (LyP1) enhanced the binding efficacy of nanocarriers with lymphogenic cancer cells. The targeted nanoformulation of activated gemcitabine (LyP1-NG-dFdCTP), when injected in subcutaneous RL7/G xenograft tumor model, demonstrated 2-fold more efficient tumor growth inhibition than gemcitabine at a higher dose. Nanogel-drug formulations exhibited no systemic toxicity during the treatment, hence extending the versatility of nucleoside analogs in the treatment of drug-resistant lymphogenic tumors.