Suicidal gene therapy in the effective control of primary human hepatocellular carcinoma as monitored by noninvasive bioimaging.

Hepatocellular carcinoma (HCC) is usually refractory to the available treatments. For cancer gene therapy purposes, real-time imaging of therapeutic gene expression is of great importance because there are multiple factors that modulate the therapeutic gene expression in a complex tumor microenvironment. As a consequence, multiple doses of therapeutic viral vectors may be required for improved efficacy. In the present study, the luciferase reporter gene and the yeast cytosine deaminase (yCD) genes were bicistronically expressed using the foot-and-mouth disease virus 2A peptide under the regulation of the cytomegalovirus (CMV) promoter. The effectiveness of the yCD/5-FC (5-fluorocytosine) killing efficacy mediated by the herpes simplex virus type 1 (HSV-1) amplicon viral vector was shown using HCC and non-HCC cell lines in vitro. In addition, in vivo experiment also showed tumor regression of a primary HCC 26-1004 tumor xenograft in tumor expressing high levels of the yCD gene (as determined by noninvasive imaging) after intratumoral injection of 1.5 × 10(6) TU HGCX-L2C HSV-1 amplicon viral vector and 5-FC administration. The HSV-1 amplicon viral vector coupled with the yCD/5-FC prodrug activated suicide gene could potentially be of use in clinical gene therapy for HCC.

Gefitinib, cisplatin, and concurrent radiotherapy for locally advanced head and neck cancer: EGFR FISH, protein expression, and mutational status are not predictive biomarkers.

BACKGROUND: Gefitinib was demonstrated to be synergistic with cisplatin and radiotherapy (RT) in in vitro studies. Biomarkers predictive of response to gefitinib in squamous cell head and neck cancer is still lacking. METHODS: Thirty-one patients with locally advanced and easily accessible primary tumor sites for biopsies were recruited. Gefitinib was started 3 weeks before the start of cisplatin/concurrent radiotherapy (CTRT) and continued during the CTRT phase and thereafter for 4 months as consolidation phase. Two baselines and a repeat tumor sample were taken after 2 weeks of gefitinib alone to study its impact on tumor gene expression. Epidermal growth factor receptor (EGFR) protein expression, FISH and mutational status, and matrix metallopeptidase 11 (MMP11) protein expression were correlated with response and survival outcome. RESULTS: The overall response rate to gefitinib alone was 9.7%. The survival outcome is as follows: median disease free 1.3 years, median survival time 2.4 years, 3-year disease free 42.9%, and 3-year overall survival 48.4%. EGFR FISH, protein expression, and mutational status did not predict for response nor survival outcome of patients. Although MMP11 overexpression did not predict for response, it predicted significantly for a poorer survival outcome. CONCLUSIONS: Gefitinib can be combined safely with cisplatin/RT. More studies are needed to uncover predictive biomarkers of benefit to gefitinib.

Targeting human glioma cells using HSV-1 amplicon peptide display vector.

Targeting cell infection using herpes simplex virus type 1 (HSV-1) vectors is a complicated issue as the process involves multiple interactions of viral envelope glycoproteins and cellular host surface proteins. In this study, we have inserted a human glioma-specific peptide sequence (denoted as MG11) into a peptide display HSV-1 amplicon vector replacing the heparan sulfate-binding domain of glycoprotein C (gC). The modified MG11:gC envelope recombinant vectors were subsequently packaged into virions in the presence of helper virus deleted for gC. Our results showed that the tropism of these HSV-1 recombinant virions was increased for human glioma cells in culture as compared with wild-type virions. The binding of these recombinant virions could also be blocked effectively by pre-incubating the cells with the glioma-specific peptide, indicating that MG11 peptide and the recombinant virions competed for the same or similar receptor-binding sites on the cell surface of human glioma cells. Furthermore, preferential homing of these virions was shown in xenograft glioma mouse model following intravascular delivery. Taken together, these results validated the hypothesis that HSV-1 binding to cells can be redirected to human gliomas through the incorporation of MG11 peptide sequence to the virions.

p16INK4A-silencing augments DNA damage-induced apoptosis in cervical cancer cells.

p16(INK4A) (p16) has been suggested to be an early biomarker for the detection of cervical cancer. However, its functional role in cervical cancer is not well characterized. In this study, we reported the consistent and significant upregulation of p16 in cervical cancer tissues when compared to both matched non-tumourous tissues of the same patient and normal cervical tissues from non-cancer patients. We have employed p16 small interfering RNA (siRNA) to dissect the role of p16 in cervical carcinogenesis. Although the silencing of p16 was accompanied by the upregulation of p53, p21 and RB in the p16 siRNA-transfected cells, no significant effect on cell cycle progression was observed. When the p16 siRNA-silenced cells were subjected to DNA damage stress including ultraviolet-irradiation and cisplatin treatments, a significantly higher percentage of apoptotic cells could be observed in the p16-siRNA silenced cells compared to control siRNA-treated cells. Moreover, induction of apoptosis was associated with the activation of p53 through phosphorylation, and this process, when studied by gene profiling experiments, involved both the intrinsic and extrinsic apoptotic pathways. The observation that silencing of p16 expression augments DNA damage-induced apoptosis in cervical cancer cells offers alternative strategies for anti-cancer therapies for human cervical cancer.

Targeting proliferating tumor cells via the transcriptional control of therapeutic genes.

We have previously reported the construction of a cell cycle-regulated HSV-1 amplicon vector (denoted as pC8-36) that confers luciferase reporter gene activities dependent on cellular divisions. However, luciferase reporter gene is well known for its relatively high sensitivity, thus, it is crucial to evaluate the therapeutic efficacy of a transcriptional targeted vector. In this report, we have engineered the FasL and FADD genes into pC8-36 and demonstrated their efficacy for the treatment of human gliomas in vitro and in vivo. Using trypan blue dye exclusion and TUNEL assay, FasL expression mediated by pC8-36 was shown to induce a significantly higher percentage of cell death in proliferating cells than those observed in the G(1)-arrested cells. The observed cell killing effect correlated well with the level of FasL protein expression when analyzed by ELISA assay. Furthermore, the incorporation of both FasL and FADD into pC8-36 resulted in the enhancement of apoptosis in the target glioma cells both in vitro and in vivo. Targeting proliferating tumor cells via the transcriptional control of therapeutic genes could potentially improve the safety and efficacy of cancer gene therapy, and thus would allow the development of strategies for more effective anticancer therapies.

Establishment of a discriminant mathematical model for diagnosis of deficiency-cold syndrome using gene expression profiling.

OBJECTIVE: To screen diagnostic markers of Deficiency-Cold syndrome by gene expression profile and to establish a discriminant mathematical milliliters model for the clinical diagnosis of this syndrome based on a support vector machine (SVM). METHODS: A family suffering from Deficiency-Cold syndrome is chosen for this study. This family has 5 patients with Deficiency-Cold syndrome and 10 normal members. The peripheral blood samples for these 5 patients and 5 normal members are tested by using cDNA microarray with 18,816 clones to get their differential expression genes. These genes are further explored to understand their biological functions and pathways through existing databases. A SVM model for clinical diagnosis is then developed based on these differential expression genes. RESULTS: A total of 83 differential expression genes were identified between patients and normal members, in which 21 genes were recorded in the FATIGO database and 16 genes were related to metabolism. Eight (8) pathways were sorted out in the KEGG database, and half pathways were associated with human metabolism. A discriminant mathematical model based on a support vector machine successfully predicted a normal person and a patient with heavy Deficiency-Cold syndrome based on their gene differential expression profiles. Thus, this model may classify the Deficiency-Cold syndrome. CONCLUSION: This work demonstrates that the differential expression genes can be used to identify normal persons and patients with Deficiency-Cold syndrome. Deficiency-Cold syndrome is mainly associated with the metabolism-related gene regulations. In addition, the discriminant mathematical model based on a support vector machine is applicable to the clinical diagnosis for Deficiency-Cold syndrome.

Generation of allo-reactive cytotoxic T lymphocytes by particle bombardment-mediated gene transfer.

Mature T lymphocytes comprise functionally distinct subsets with discrete roles in the regulation of the immune response. The cellular basis of the anti-tumor effect is now understood to involve the activation and expansion of tumor-specific cytotoxic T lymphocytes (CTL). To immuno-potentiate the generation of CTL, we have employed the biolistic system for the genetic immunization of mice. Here, we report the efficient generation of anti-H-2Kb allo-reactive CTL by particle acceleration-mediated genetic immunization of mouse spleen cells with H-2Kb DNA. The insertion and expression of exogenous gene into host spleen cells following in situ genetic inoculation to effect the generation of a cellular immune response may permit novel alternative strategies for immunotherapy.

The influence of interleukin-2 on vasopressin and oxytocin gene expression in the rodent hypothalamus.

There is growing evidence of interactions between the central nervous system and the immune system. We present evidence that the cytokine interleukin-2 (IL-2) influences expression of the genes encoding the neuropeptides vasopressin (VP) and oxytocin (OT) in the hypothalamus of the nude mouse. A single injection of recombinant mouse IL-2 (rmIL-2) caused a significant increase in VP and OT mRNA levels in the hypothalamus of nude mice. This effect was specific to the nude mouse. These observations stress the potential value of the nude mouse for studying interactions between the central nervous system (CNS) and the immune system.

HLA genotyping of colorectal carcinoma in the Chinese population.

The HLA-DR genotypes of 61 primary colorectal carcinomas obtained from patients of Chinese origin were determined by using DNA-RFLP. No increase or decrease of a particular HLA genotype could be ascertained with the disease, although we detected an antigen frequency of 29.5% for the serologically ill-defined DR"X3" specificity. We identified and sequenced HLA-DRB1 and DRB3 genes from the DR"X3" haplotype. The DR"X3" DRB1 gene was found to be identical to DRB1*1201 (DR5[w12]). A unique observation is its unusual linkage with DRB3*0101 (DRw52a) or DRB3*0301 (DRw52c) instead of the usual linkage with DRB3*0201/2 (DRw52b). These associations are rare in whites and blacks.

Bis(7)-tacrine, a novel dimeric AChE inhibitor, is a potent GABA(A) receptor antagonist.

Heptylene-linked bis-(9-amino-1,2,3,4-tetrahydroacridine) (bis(7)-tacrine) is a potential palliative therapeutic agent for Alzheimer's disease (AD), on the basis of its superior acetylcholinesterase (AChE) inhibition and memory-enhancing potency relative to tacrine. In this study we report that bis(7)-tacrine exhibits a potentially complementary central nervous system action, antagonism of GABA(A) receptor function. Bis(7)-tacrine displaced [3H]muscimol from rat brain membranes with an apparent Ki of 6.0 microM; tacrine and physostigmine were shown to be 18 and 170 times less potent, respectively. In whole-cell patch-clamp recordings, bis(7)-tacrine inhibited GABA-induced inward current with an IC50 of 5.6 microM, and shifted the GABA concentration-response curve to the right in a parallel manner. These results suggest that bis(7)-tacrine is a competitive antagonist of the GABA(A) receptor.

Immunotherapy of human cancers.

Advances in molecular biology technologies have significantly facilitated the identification of functional genes which cause, promote or control a variety of human diseases. Through recombinant DNA and polymerase chain reaction technologies, individual genes responsible for specific diseases have been identified, and consequently, the prospect that these diseases might be "cured" through replacement of the defective genes by their normal counterparts become distinct possibilities. Therefore, the goal of gene therapy is to apply this technology to the treatment of human diseases. In addition to its logical role for the correction of inherited diseases caused by a missing or defective gene product, gene therapy also holds promise for treatment of acquired disorders such as human cancer through the introduction of genes whose products have been implicated in controlling the growth of cancer. In this report, we present our results on the introduction of allogeneic major histocompatibility complex genes into cancer cells as an approach to increase the host's immune response against cancer. Various gene delivery strategies have been optimized for the introduction of DNA into various human tumour cells and these data are presented.

The innovative evolution of cancer gene and cellular therapies.

We provide an overview of the latest developments in cancer gene therapy--from the bench to early-stage clinical trials. We describe the most recent work of worldwide teams including experienced scientists and clinicians, reflecting the recent emergence of gene therapy from the 'Valley of Death'. The treatment efficacy of clinical gene therapy has now been shown in a number of diseases including cancer and we are observing a renewed interest by big pharmaceutical and biotechnology companies most obviously demonstrated by Amgen's acquisition of Biovex for up to USD$1 billion. There is an opportunity to be cautiously hopeful regarding the future of gene therapy in the clinic and we review here some of the most recent progress in the field.

MicroRNAs involved in regulating epithelial-mesenchymal transition and cancer stem cells as molecular targets for cancer therapeutics.

One of the major challenges in cancer gene therapy is the identification of functionally relevant tumor-specific genes as the therapeutic targets. MicroRNAs (miRNAs) are a class of small, 22-25 nucleotides, endogenously expressed noncoding RNA. miRNAs are important genetic regulators: one miRNA can possibly target multiple genes and they can function as tumor promoters (oncogenic miRNAs, oncomirs) or tumor suppressors (anti-oncomirs). Therefore, the identification of misregulated miRNAs in cellular signaling pathways related to oncogenesis can have profound implications for cancer therapy. The epithelial-mesenchymal transition (EMT) converts epithelial cells into mesenchymal cells, a normal embryological process that frequently get activated during cancer invasion and metastasis. Recent evidence also supports the presence of a small subset of self-renewing, stem-like cells within the tumor mass that possess the capacity to seed new tumors and they have been termed 'cancer stem cells (CSC)'. Conceivably, these CSCs could provide a resource for cells that cause therapy resistance. Although the cell origin of CSCs remains to be fully elucidated, a growing body of evidence has demonstrated that the biology of EMT and CSCs is tightly linked with the sequences and compositions of miRNA molecules. Therefore, targeting miRNAs involved in EMT and CSCs regulation can provide novel miRNA-based therapeutic strategies in oncology.

The tumor suppressor function of LECT2 in human hepatocellular carcinoma makes it a potential therapeutic target.

Vascular invasion is one of the clinicopathologic features that are associated with early recurrence of human hepatocellular carcinoma (HCC). In this study, we have employed high-density Affymetrix oligonucleotide GeneChips (Affymetrix, Santa Clara, CA) to compare the expression profiles of HCC with and without vascular invasion. Data mining of the gene expression database established revealed that leukocyte cell-derived chemotaxin-2 (LECT2) transcripts were downregulated in HCC patients with vascular invasion. Expression of LECT2 in human HCC biopsies was significantly reduced (P < 0.0001, fold change = -7.2) when compared with non-tumorous adjacent liver tissues. The reduction of LECT2 expression was significantly correlated with the early recurrent and poor prognosis of the patient (P = 0.024). To validate the ability of LECT2 to repress the growth of HCC, an adenoviral vector encoding the secreted human LECT2 (AdLECT2) was introduced into the human HCC cell lines Hep3B and PLC/PRF/5, which do not express endogenous LECT2. Over-expression of LECT2 resulted in the significant inhibition of in vitro migration and invasion of the AdLECT2-transfected HCC cells. Additionally, over-expression of AdLECT2 in subcutaneous Hep3B tumor xenografts in athymic nude mice resulted in significant inhibition of tumor growth (P < 0.05). In summary, our data not only demonstrated that LECT2 is a candidate prognostic marker of human HCC, but also that therapeutic strategies targeting LECT2 expression is a promising therapy for human HCC.

Identification of unique and common low abundance tumour-specific transcripts by suppression subtractive hybridization and oligonucleotide probe array analysis.

Most human cancers are characterized by genetic aberrations accompanied by altered expression and function of numerous genes. Applying genome-wide, microarray gene expression analysis to identify deregulated genes in different tumour types can provide potential gene candidates as diagnostic and prognostic tools and promising targets for drug development. However, the detection of deregulated genes with low levels of expression remains a major challenge. In this study, we have designed a strategy, termed modified suppression subtractive hybridization (mSSH), to identify genes encoding rare transcripts. The strategy entails incorporating the T(7)-promoter sequence at the 5' end of the noncoding cDNA strand during first strand cDNA synthesis to generate unidirectional antisense RNA from the resultant cDNA following conventional SSH. These transcripts are subsequently analysed by Affymetrix oligonucleotide gene arrays. Here, we have used five hepatocellular carcinoma (HCC), five breast carcinoma and four nasopharyngeal carcinoma (NPC) biopsies separately as testers and their corresponding normal biopsies as drivers to enrich for low abundance tumour type-specific transcripts. The total detectable number of probe sets following mSSH was reduced almost 10-fold in comparison to those detected for the same resected tumour tissues without undergoing subtraction, thus yielding a subtraction efficacy of over 90%. Using this experimental approach, we have identified 48 HCC-specific, 45 breast carcinoma-specific, and 83 NPC-specific genes. In addition, 115 genes were upregulated in all the three cancer types. When compared to gene-profiling data obtained without mSSH, the majority of these identified transcripts were of low abundance in the original cancer tissues. mSSH can therefore serve as a comprehensive molecular strategy for pursuing functional genomic studies of human cancers.

HSV-1 amplicon viral vector-mediated gene transfer to human bone marrow-derived mesenchymal stem cells.

Human bone marrow-derived mesenchymal stem cells (BM-hMSCs) are nonhematopoietic stem cells that have the potential to differentiate into adipocytes, osteocytes and chondrocytes. Because of its propensity to migrate to the sites of injury and the ability to expand them rapidly, BM-hMSCs have been exploited as potential gene transfer vehicles to deliver therapeutic genes. Herein, we evaluated the feasibility of employing herpes simplex virus type I (HSV-1) amplicon viral vector as a gene delivery vector to BM-hMSCs. High transduction efficiencies were consistently observed in different isolates of BM-hMSCs following infection with HSV-1 amplicon viral vectors. Furthermore, we demonstrated that transduction with HSV-1 amplicon viral vector did not alter the intrinsic properties of the BM-hMSCs. The morphology and cellular proliferation of the transduced BM-hMSCs were not altered. Chromosomal stability, as confirmed by karyotyping and soft agar colony assays, of the transduced BM-hMSCs was not affected. Similarly, transduction with HSV-1 amplicon viral vectors has no effect on the pluripotent differentiation potential and the tumor tropism of BM-hMSCs. Taken together, these results demonstrated that BM-hMSCs could be transduced efficiently by HSV-1 amplicon viral vector in an 'inert' manner and thus enable strategies to express potential therapeutic genes in BM-hMSCs.

Nanosized bioceramic particles could function as efficient gene delivery vehicles with target specificity for the spleen.

We have compared the ability of several nanosized bioceramic particles including negatively charged silica (SiO(2)), neutrally charged hydroxyapatite (HA) and positively charged zirconia (ZrO(2)) nanoparticles as non-viral vectors for efficient in vivo gene delivery. A mixture of highly monodispersed aqueous suspension of HA or SiO(2) nanoparticles, coated with protamine sulfate (PS), complexed efficiently with plasmid DNA and significantly enhanced transgene expression in vitro. In comparison, ZrO(2) nanoparticles gave poor transfection efficiency under similar conditions tested. It was also determined that, under the same conditions, PS-SiO(2)-DNA, but not PS-HA-DNA-nanoplexes, were able to mediate efficient transgene expression in vitro in the presence of 50% serum. Intraperitoneal injections of PS-SiO(2)-luciferase DNA nanoplexes targeted the highest level of transgene expression in the spleen of recipient mice that lasted for more than 48 h. Injection of PS-SiO(2)-pNGVL-hFLex-MUC-1 nanoplexes was able to mediate the production of Flt-3L in the sera of recipient mice. Simultaneously, the production of Flt-3L was accompanied by the stimulation of IL-2 and interferon-gamma (IFN-gamma). Most importantly, the injection of PS-SiO(2)-pNGVL-hFLex-MUC-1 nanoplexes could mount potent anti-tumour specific immune responses that led to the subsequent regression of parental tumor cells containing the muc-1 determinant.

Intramuscular immunization with plasmid coexpressing tumour antigen and Flt-3L results in potent tumour regression.

Dendritic cells (DC) are professional antigen-presenting cells capable of initiating a potent primary immune response, making them an attractive target for cancer immunotherapy. Flt-3 ligand (Flt-3L) is a haematopoietic growth factor that efficiently induces DC expansion in vivo. To achieve a more efficient and effective method of priming tumour-specific, DC-mediated immune response, we generated a DNA vaccine comprising both human Flt-3L and the tumour antigen, MUC-1 (pNGVL-hFLex-MUC-1). We report that pNGVL-hFLex-MUC-1 is able to induce antigen-specific CTL immunity in vivo, resulting in a potent anti-tumour response, and that the Flt-3L component is essential to the efficacy of the DNA vaccine. Moreover, the route of immunization is critical in determining the type of immune response generated; intramuscular (i.m.) immunization with pNGVL-hFLex-MUC-1 conferred tumour protection in contrast to poor response with hydrodynamic-based intravenous delivery. Post-i.m. immunization, we observed a massive infiltration of mononuclear cells to the injection site, comprised predominantly of CD11c(+)/CD8alpha(-) DC. Therefore, we propose that Flt-3L acts as an adjuvant to recruit DC, thereby priming the anti-tumour response. However, systemic expansion of DC prior to immunization did not enhance the specific cellular response, suggesting that it is in situ recruitment or expansion of DC that is critical for pNGVL-hFLex-MUC-1 potency.

Systemic administration of naked DNA with targeting specificity to mammalian kidneys.

A major challenge for gene therapy is to be able to deliver efficiently the gene of interest to specific cell types. Here we describe a safe and simple effective naked DNA gene delivery method, via inferior vena cava (IVC) injection, to the recipient's kidneys. It was further demonstrated that gene expression was concentrated in the proximal tubular epithelial cells of the cortico-medullary region of the kidney. Confocal microscopy analyses demonstrated the presence of the exogenous DNA in the renal cell membrane 10 min postgene delivery. However, it was only by 30 min that the presence of the exogenous DNA could be detected in the cell cytoplasm and in the nuclei of the renal cells. Stable expression of the beta-galactosidase gene could be detected for up to 35 days and no toxicity or any adverse pathological effect associated with the delivery method could be observed. Importantly, this IVC gene delivery method could promote the targeting of genes to carcinoma established in the kidney of SCID mice. These results provide the first evidence to support that stable gene expression could be achieved in the renal cells of kidney and the established carcinoma in the kidneys following in vivo gene delivery with naked DNA and could therefore provide the potential to design protocols for the gene therapy of the kidney diseases.

Transgenic animals and the study of the immune system.

Transgenic technology, the introduction of genetic information into the germ line of an animal to alter its genetic constitution stably, provides a powerful tool for studying the development, functions, and malfunctions of complex biological systems. The main advantage has been that it is possible to study the gene functioning in its natural milieu. This is particularly informative when the genes have been manipulated such that the regulation and tissue specificity of expression are altered. Although transgenic animals bear the introduced gene in every tissue, expression of that gene may be widespread or directed to particular cell lineages, depending on the regulatory sequences chosen.