Gene therapy for lung cancer

Gene therapy has received considerable attention and some speculation as to its value. Although few patients have been treated, the preliminary results of the phase I lung cancer gene therapy clinical trials are very promising. Clinically relevant basic research in the molecular pathogenesis and immunology of lung cancer is progressing. As improved vector technologies are developed, new opportunities will be available to initiate lung cancer gene therapy trials that are based on a more detailed understanding of lung cancer biology. In conclusion, although important biologic and technical questions remain unanswered, recent research suggests that gene therapy will have a profound impact on lung cancer treatment.     

Gene therapy for breast cancer

Gene therapy for breast cancer is still in the very early stages of development. Many of the molecular strategies that have been proposed are also being developed for other cancers. Their application to breast cancer, however, needs to address several issues specific to this disease such as the widespread nature of metastases, the indolent growth of the tumor cells, and the production by the tumor of immunosuppressive agents. Nonetheless, these approaches appear promising, particularly those that employ a combination of strategies. Gene therapies that affect the biology of breast cancer cells or regulate host immune mechanisms have been most successful and may be paired with existing therapies for breast cancer.     

Gene therapy for hepatic micrometastasis of murine colon carcinoma

BACKGROUNDS/AIMS: Pit cells are located in the hepatic sinusoids and are organ-associated natural killer cells that contribute to immune surveillance in the liver. In the present study, the interleukin-2 gene was introduced into hepatocytes using an adenovirus vector to induce interleukin-2 production in an attempt to enhance the natural killer activity of pit cells, leading to inhibition of metastasis of colon carcinoma. METHODS: The recombinant adenovirus vector "Adex1CAmIL2" was constructed by inserting an expression unit which was composed of the CAG promotor (cytomegalovirus enhancer plus chicken beta-actin promotor), murine interleukin-2 cDNA, and a rabbit beta-globin polyadenylation signal. After administration of Adex1CAmIL2 to mice (4x10(7) pfu per animal), the expression of murine interleukin-2 in hepatocytes was examined by immunostaining and in situ hybridization, and the natural killer activity of hepatic mononuclear cells was measured. Inhibition of hepatic metastasis of colon carcinoma was examined after infusion of colon 38 tumor cells into the superior mesenteric vein. RESULTS: After administration of Adex1CAmIL2, interleukin-2 mRNA expression was demonstrated in hepatocytes until day 7, and the serum interleukin-2 level was increased. The natural killer activity of hepatic mononuclear cells was markedly enhanced for 7-10 days. Hepatic metastasis was inhibited by administration of Adex1CAmIL2 until day 7 after tumor cell inoculation. CONCLUSION: These results suggest that gene therapy using Adex1CAmIL2 could be potentially useful for inhibiting hepatic micrometastasis by enhancing the natural killer activity of pit cells.     

Gene therapy of cancer

Retroviral-mediated gene transfer has permitted the development of clinical protocols for the study and treatment of cancer. These protocols can be divided into gene-labeling and gene therapy proposals. Labeling studies include the tracking of tumor infiltrating lymphocytes (TIL) following the administration of those cells, and the detection, at the time of relapse, of tumor cells from transplanted autologous bone marrow. Most gene therapy protocols are designed to induce an immune attack against the tumor by inserting genes into tumor cells themselves. Although uncertainty about the safety of the procedure still exists, gene therapy of cancer holds much promise as an effective treatment modality.     

Gene therapy of cancer

OBJECTIVE: To provide a review of the basic concepts and terminology of human genetics, the clinical application and risks of gene therapy, and ethical and societal issues. DATA SOURCES: Review articles, research studies, and book chapters related to genetics and human gene therapy. CONCLUSIONS: The genetic changes that play a role in the development of cancer have begun to be elucidated, and these discoveries have led to strategies to destroy cancers by correcting genetic defects or manipulating genes to induce tumoricidal activities. Gene therapy is a novel investigational intervention that is constantly evolving. IMPLICATIONS FOR NURSING PRACTICE: Oncology nurses will need an increased understanding of cellular biology, genetics, and genetics engineering. Major considerations for nursing practice include patient and family education, informed consent, side effects, and ethical and societal issues.     

Gene transfer therapy in cancer

Gene transfer techniques have now achieved clinical realization in the wake of recent advances in recombinant DNA technology, together with increased understanding of the molecular biology and immunology of cancer. These novel treatments, and their applications and limitations merit intensive study.     

Feasibility of photodynamic therapy using endogenous photosensitization for colon cancer

A novel approach to photodynamic therapy (PDT) involves endogenous photosensitization by the oral administration of delta-aminolevulinic acid (ALA), a naturally occurring substance that is the precursor of protoporphyrin IX (PpIX). A 60-year-old man with adenocarcinoma of the sigmoid colon received ALA, 60 mg/kg by mouth. Six hours later, when the plasma level of PpIX had peaked, the tumor was exposed locally to red light at 633 nm to activate PpIX. Endoscopy and biopsy findings subsequent to this treatment showed unequivocal visible changes and necrosis. Six months later, the patient again underwent successful treatment without adverse effects. This report suggests a role for PDT using endogenous photosensitization in certain circumstances involving adenocarcinoma of the large intestine.     

Gene therapy for hematological malignancies

The management of avascular necrosis of the capitellum of the adolescent elbow continues to be a dilemma. This article is a critical retrospective analysis of 12 pediatric patients (mean age at surgery 14.5 years) who underwent arthroscopic debridement alone followed by early range of motion. Follow-up at a mean of 3.2 years (range, 2.0 to 5.7 years) indicated that the average flexion contracture improved from 23 degrees preoperatively to 10 degrees postoperatively. All patients had remodeling of the capitellum by plain radiographs; however, five patients had associated enlargement of the radial head. Eleven patients had minimal mechanical symptoms after the procedure and were highly satisfied. One patient had substantial enlargement of the radial head with continued loss of supination and mechanical symptoms requiring radial head resection 2 years after the index procedure. Five patients had a triangular avulsion fragment present off the lateral capsule. A statistically significant worse subjective outcome was associated with the presence of this fragment (P < .005). There were no complications.     

Gene therapy for cerebrovascular disease

OBJECTIVE: To review the principles of and the experimental and clinical results of gene therapy for cerebrovascular disease. METHODS: Literature review. RESULTS: Vectors for gene transfer into the brain or into the cerebral vasculature include naked plasmid deoxyribonucleic acid, cationic liposomes, and viruses such as adenovirus, retrovirus, adeno-associated virus, and herpes simplex virus. Experiments using these vectors showed that intra- or perivascular application to systemic arteries can lead to transfection and expression of a foreign transgene in the adventitia and the endothelium. Intrathecal administration can lead to transfection and foreign transgene expression in leptomeningeal cells as well as in fibroblasts of blood vessel adventitia. Biological effects demonstrated thus far include increased nitric oxide production by transfection of cerebral arterial adventitia with adenovirus expressing nitric oxide synthase. Adenoviruses carrying foreign genes have been used to decrease neuronal damage in cerebral ischemia and to decrease blood pressure in spontaneously hypertensive rats. Vectors and therapeutic applications for gene therapy are evolving rapidly. CONCLUSION: Gene therapy for cerebrovascular disease is likely to have clinical application in the near future and will have a major impact on neurosurgery. Neurosurgeons will need to be aware of the literature in this area.     

Gene therapy for malignant gliomas

Malignant gliomas are attractive targets for gene therapy because of their relatively well-localized distribution. Several new strategies have been devised that target different aspects of glioma biology. Gene transfer can be used to synthesize chemotherapy drugs that block DNA synthesis within these highly mitotic tumors. New genes can be introduced that restore the functions of mutated tumor suppressor genes or block the molecular pathways needed for tumor angiogenesis. Alternatively, the immune response to these tumors can be augmented by the local production of cytokines. Finally, viruses themselves can be used as tumoricidal agents by designing viruses that selectively replicate and destroy tumor cells. The advantages and limitations of these approaches are discussed in the context of their possible application to the treatment of these highly lethal malignancies.     

Gene therapy for primary immunodeficiency

The mechanisms by which monocytes from patients infected with human immunodeficiency virus (HIV) have reduced growth inhibitory activity against Cryptococcus neoformans was examined. Monocyte-enriched peripheral blood mononuclear cells from 12 HIV-seropositive donors with CD4 cell counts of 10-210 cells/mm3 (median, 85) and HIV-seronegative donors were compared in assays to determine the binding and phagocytosis of C. neoformans and the respiratory burst and degranulation in response to C. neoformans and zymosan. Monocytes from HIV-infected and uninfected persons bound and ingested C. neoformans equally well; however, generation of hydrogen peroxide and specific release of beta-glucuronidase in response to C. neoformans was significantly reduced in monocyte-enriched cells from the HIV-infected donors. The impaired anticryptococcal activity of monocytes from persons with HIV may be related to defects in both oxidative and nonoxidative effector pathways that occur after the binding and internalization of the organism.     

Adjuvant therapy for stage II colon cancer after complete resection. Provincial Gastrointestinal Disease Site Group

GUIDELINE QUESTION: Should patients with resected stage II colon cancer receive adjuvant therapy? OBJECTIVE: To make recommendations regarding the use of adjuvant therapy in the treatment of resected stage II colon cancer. OUTCOMES: Overall survival is the primary outcome of interest. Secondary outcomes are disease-free survival and adverse effects of the treatment regimens. PERSPECTIVE (VALUES): Evidence was selected and reviewed by 2 members of the Provincial Gastrointestinal Disease Site Group (GI DSG) of the Cancer Care Ontario Practice Guidelines Initiative. The recommendations resulting from this review have been approved by the GI DSG, which comprise medical and radiation oncologists, surgeons and epidemiologists. Community representatives did not participate in the development of this practice guideline but will do so in future guidelines development. QUALITY OF EVIDENCE: There are 25 published randomized controlled trials (RCTs) and 1 meta-analysis. The GI DSG pooled data from 11 of the 25 RCTs that provided adequate data. BENEFITS: The 25 RCTs are grouped according to the type of therapy and whether the control patients received no treatment (observation) or other adjuvant therapy after resection. Because the trials usually included patients with stage II and III cancer, the complete trial results and those for a subset of patients with stage II disease were analysed. Although the overall trial results showed a survival benefit for adjuvant treatments, the benefit was not significant for stage II patients. A meta-analysis of 11 trials comparing adjuvant treatment with observation in patients with stage II cancer indicated no significant reduction in the odds ratio (OR) for death (OR 0.83; 95% confidence interval [CI] 0.62 to 1.10). The OR for death among patients receiving chemotherapy by portal vein infusion (PVI) was 0.62 (95% CI 0.35 to 1.11). HARMS: The toxic effects of 5-fluorouracil (5-FU) with either levamisole or leucovorin, or both, were mild to moderate and consisted mostly of stomatitis, diarrhea and myelosuppression; 5% of patients required hospital admission. 5-FU plus levamisole was associated with transient neurotoxic effects in 18% of patients. Toxic effects associated with PVI were mild, rare and mostly consisted of leukopenia and diarrhea; 1% of patients experienced bowel perforation. PRACTICE GUIDELINE: Adjuvant therapy is not recommended at this time for the routine management of patients with resected stage II colon cancer. Patients with stage II disease and high-risk factors (bowel obstruction, tumour adhesion, invasion, perforation or aneuploidy) have a poorer prognosis, similar to that of patients with stage III colon cancer. For individual management, these patients should be made aware of their prognosis; treatment can be considered after the uncertainty of the value of adjuvant therapy has been explained to the patient. The enrolment of patients with high-risk stage II disease in clinical trials is encouraged. Trials comparing adjuvant therapy with observation are needed and are ethically acceptable in stage II colon cancer.