Dong M. Shin

Nanoparticle therapeutics: an emerging treatment modality for cancer

Nanoparticles — particles in the size range 1–100 nm — are emerging as a class of therapeutics for cancer. Early clinical results suggest that nanoparticle therapeutics can show enhanced efficacy, while simultaneously reducing side effects, owing to properties such as more targeted localization in tumours and active cellular uptake. Here, we highlight the features of nanoparticle therapeutics that distinguish them from previous anticancer therapies, and describe how these features provide the potential for therapeutic effects that are not achievable with other modalities. While large numbers of preclinical studies have been published, the emphasis here is placed on preclinical and clinical studies that are likely to affect clinical investigations and their implications for advancing the treatment of patients with cancer.

Therapeutic Nanoparticles for Drug Delivery in Cancer

Cancer nanotherapeutics are rapidly progressing and are being implemented to solve several limitations of conventional drug delivery systems such as nonspecific biodistribution and targeting, lack of water solubility, poor oral bioavailability, and low therapeutic indices. To improve the biodistribution of cancer drugs, nanoparticles have been designed for optimal size and surface characteristics to increase their circulation time in the bloodstream. They are also able to carry their loaded active drugs to cancer cells by selectively using the unique pathophysiology of tumors, such as their enhanced permeability and retention effect and the tumor microenvironment. In addition to this passive targeting mechanism, active targeting strategies using ligands or antibodies directed against selected tumor targets amplify the specificity of these therapeutic nanoparticles. Drug resistance, another obstacle that impedes the efficacy of both molecularly targeted and conventional chemotherapeutic agents, might also be overcome, or at least reduced, using nanoparticles. Nanoparticles have the ability to accumulate in cells without being recognized by P-glycoprotein, one of the main mediators of multidrug resistance, resulting in the increased intracellular concentration of drugs. Multifunctional and multiplex nanoparticles are now being actively investigated and are on the horizon as the next generation of nanoparticles, facilitating personalized and tailored cancer treatment.

Retrovirus-mediated wild-type p53 gene transfer to tumors of patients with lung cancer

A retroviral vector containing the wild–type p53 gene under control of a β–actin promoter was produced to mediate transfer of wild–type p53 into human non–small cell lung cancers by direct injection. Nine patients whose conventional treatments failed were entered into the study. No clinically significant vector–related toxic effects were noted up to five months after treatment. In situ hybridization and DNA polymerase chain reaction showed vector–p53 sequences in posttreatment biopsies. Apoptosis (programmed cell death) was more frequent in posttreatment biopsies than in pretreatment biopsies. Tumor regression was noted in three patients, and tumor growth stabilized in three other patients.

Recent Advances in Head and Neck Cancer

There are more than half a million incident cases of squamous-cell carcinoma of the head and neck worldwide each year, primarily affecting the oropharynx, oral cavity, hypopharynx, and larynx. This review considers the biologic features of these tumors, including the role of human papillomavirus as a risk factor for cancer of the oropharynx. New therapies are considered, along with management approaches.

Nanotechnology in cancer therapeutics: bioconjugated nanoparticles for drug delivery

Nanotechnology refers to the interactions of cellular and molecular components and engineered materials—typically, clusters of atoms, molecules, and molecular fragments into incredibly small particles—between 1 and 100 nm. Nanometer-sized particles have novel optical, electronic, and structural properties that are not available either in individual molecules or bulk solids. The concept of nanoscale devices has led to the development of biodegradable self-assembled nanoparticles, which are being engineered for the targeted delivery of anticancer drugs and imaging contrast agents. Nanoconstructs such as these should serve as customizable, targeted drug delivery vehicles capable of ferrying large doses of chemotherapeutic agents or therapeutic genes into malignant cells while sparing healthy cells. Such “smart” multifunctional nanodevices hold out the possibility of radically changing the practice of oncology, allowing easy detection and then followed by effective targeted therapeutics at the earliest stages of the disease. In this article, we briefly discuss the use of bioconjugated nanoparticles for the delivery and targeting of anticancer drugs. [Mol Cancer Ther 2006;5(8):1909–17]

Phase II Multicenter Study of the Epidermal Growth Factor Receptor Antibody Cetuximab and Cisplatin for Recurrent and Refractory Squamous Cell Carcinoma of the Head and Neck

PURPOSE This multicenter phase II study was undertaken to define the efficacy and safety of cetuximab, an antiepidermal growth factor receptor chimeric human and murine monoclonal antibody, administered with cisplatin to patients with refractory metastatic or recurrent squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS One hundred thirty-two patients were to receive two 3-week cycles with cisplatin/paclitaxel or cisplatin/fluorouracil. Patients (n = 30) with a complete or partial response continued standard therapy. Seventy-six patients with stable disease (SD; n = 51) or progressive disease (PD/1; n = 25) received combination therapy with cetuximab (400 mg/m2 intravenously on day 1, then 250 mg/m2/wk) and cisplatin (75 or 100 mg/m2 intravenously on day 1 every 3 weeks). The protocol was subsequently amended to enroll patients who had developed PD within 90 days after platinum-based therapy (PD/2; n = 54). RESULTS Five patients (20%) in PD/1, three patients (6%) in PD/2, and nine patients (18%) with SD achieved an objective response. Median duration of response was 4.2, 4.1, and 7.4 months for the PD/1, PD/2, and SD groups, respectively, with median overall survival times of 6.1, 4.3, and 11.7 months. The most common toxicities were anemia, acne-like skin rash, leukopenia, fatigue and malaise, and nausea and vomiting. Seven patients (5%) developed a grade 3 or 4 hypersensitivity reaction to cetuximab. CONCLUSION Cetuximab and cisplatin is an active regimen in refractory SCCHN. The relative contribution of cetuximab is better defined in a single-agent trial. Cetuximab did not exacerbate cisplatin toxicity but was associated with skin rash in a majority of patients and occasional serious allergic reactions. Further study of this compound is warranted.

Perspectives for Cancer Prevention With Natural Compounds

Cancer is the second leading cause of death in the United States. Despite the estimated 565,650 deaths in 2008 of Americans as a result of cancer, it is mostly a preventable disease. Simply by modification of diet, maintenance of optimum body weight, and regular physical activity, 30% to 40% of all instances of cancer could be prevented. Modification of diet alone by increasing vegetable and fruit intake could prevent 20% or more of all cases of cancer and may potentially prevent approximately 200,000 cancer-related deaths annually. Because of their safety, low toxicity, antioxidant properties, and general acceptance as dietary supplements, fruits, vegetables, and other dietary elements (phytochemicals and minerals) are being investigated for the prevention of cancer. Extensive research over the past several decades has identified numerous dietary and botanical natural compounds that have chemopreventive potential. In this review, we discuss promising natural chemopreventive compounds, their molecular targets, and their mechanisms, which may help the further design and conduct of preclinical and clinical trials.

Targeted magnetic iron oxide nanoparticles for tumor imaging and therapy

Magnetic iron oxide (IO) nanoparticles with a long blood retention time, biodegradability and low toxicity have emerged as one of the primary nanomaterials for biomedical applications in vitro and in vivo. IO nanoparticles have a large surface area and can be engineered to provide a large number of functional groups for cross-linking to tumor-targeting ligands such as monoclonal antibodies, peptides, or small molecules for diagnostic imaging or delivery of therapeutic agents. IO nanoparticles possess unique paramagnetic properties, which and generate significant susceptibility effects resulting in strong T2 and T2* contrast, as well as T1 effects at very low concentrations for magnetic resonance imaging (MRI), which is widely used for clinical oncology imaging. We review recent advances in the development of targeted IO nanoparticles for tumor imaging and therapy.

Cancer Prevention With Natural Compounds

Botanical and nutritional compounds have been used for the treatment of cancer throughout history. These compounds also may be useful in the prevention of cancer. Population studies suggest that a reduced risk of cancer is associated with high consumption of vegetables and fruits. Thus, the cancer chemopreventive potential of naturally occurring phytochemicals is of great interest. There are numerous reports of cancer chemopreventive activity of dietary botanicals, including cruciferous vegetables such as cabbage and broccoli, Allium vegetables such as garlic and onion, green tea, Citrus fruits, soybeans, tomatoes, berries, and ginger, as well as medicinal plants. Several lead compounds, such as genistein (from soybeans), lycopene (from tomatoes), brassinin (from cruciferous vegetables), sulforaphane (from asparagus), indole-3-carbinol (from broccoli), and resveratrol (from grapes and peanuts) are in preclinical or clinical trials for cancer chemoprevention. Phytochemicals have great potential in cancer prevention because of their safety, low cost, and oral bioavailability. In this review, we discuss potential natural cancer preventive compounds and their mechanisms of action.

Phase II study of docetaxel for advanced or metastatic platinum-refractory non-small-cell lung cancer.

PURPOSE We conducted a phase II study to determine the response to and toxicity of docetaxel (Taxotere; Rhône-Poulenc Rorer Pharmaceuticals, Inc, Collegeville, PA) in patients with advanced non-small-cell lung cancer refractory to prior platinum-containing chemotherapy (PCC) regimens. PATIENTS AND METHODS Forty-four patients with stage IIIb or IV platinum-refractory non-small-cell lung cancer were treated with 100 mg/m2 of docetaxel intravenously over 1 hour every 3 weeks. The responses of 42 of 44 patients were assessable. Most patients had a Zubrod performance status of 1; the predominant histologic type was adenocarcinoma (61%), and 91% of patients had stage IV disease. RESULTS Nine of 42 assessable patients (21%) achieved a partial response to treatment. The median response duration (from response to progression) was 17 weeks, and the projected median survival duration of all patients is 42 weeks (51 weeks for adenocarcinoma and 22 weeks for nonadenocarcinoma). Grade 3/4 neutropenia occurred in 85% of patients and was associated with fever that required intravenous antibiotics in 16% of patients (3% of cycles). Other acute side effects included easily treated hypersensitivity reactions and dermatitis. Cumulative side effects included fluid retention and neuropathy. CONCLUSION Docetaxel administered at 100 mg/m2 intravenously every 3 weeks has notable activity against platinum-refractory non-small-cell lung cancer, with a 21% major response rate. Primary side effects were neutropenia, hypersensitivity, and fluid retention.