A review of the literature on the use of CRISPR/Cas9 gene therapy to treat hepatocellular carcinoma

Noncoding RNAs instruct the Cas9 nuclease to site speifillyl cleave DNA in the CRISPR/Cas9 system.Despite the high incidence of hepatocellular carcinoma(HCC),the patient's outcome is poor.As a result of the emergence of therapeutic resistance in HCC patients,dlinicians have faced difficulties in treating such tumor.In addition,CRISPR/Cas9 screens were used to identify genes that improve the dlinical response of HCC patients.It is the objective of this article to summarize the current understanding of the use of the CRISPR/Cas9 system for the treatment of cancer,with a particular emphasis on HCC as part of the current state of knowledge.Thus,in order to locate recent developments in oncology research,we examined both the Scopus database and the PubMed database.The ability to selectively interfere with gene expression in combinatorial CRISPR/Cas9 screening can lead to the discovery of new effective HCC treatment regimens by combining clinically approved drugs.Drug resistance can be overcome with the help of the CRISPR/Cas9 system.HCC signature genes and resistance to treatment have been uncovered by genome-scale CRISPR activation screening although this method is not without limitations.It has been extensively examined whether CRISPR can be used as a tool for disease research and gene therapy.CRISPR and its applications to tumor research,particularly in HCC,are examined in this study through a review of the literature.

The concept of gene therapy for glaucoma:the dream that has not come true yet

Gene therapies,despite of being a relatively new therapeutic approach,have a potential to become an important alternative to current treatment strategies in glaucoma.Since glaucoma is not considered a single gene disease,the identified goals of gene therapy would be rather to provide neuroprotection of retinal ganglion cells,especially,in intraocular-pressure-independent manner.The most commonly reported type of vector for gene delivery in glaucoma studies is adeno-associated virus serotype 2 that has a high tro pism to retinal ganglion cells,res ulting in long-term expression and low immunogenic profile.The gene thera py studies recruit inducible and genetic animal models of optic neuropathy,like DBA/2J mice model of high-tension glaucoma and the optic nerve crush-model.Reported gene therapy-based neuroprotection of retinal ganglion cells is targeting specific genes translating to growth factors(i.e.,brain derived neurotrophic factor,and its receptor TrkB),regulation of apoptosis and neurodegeneration(i.e.,Bcl-xl,Xiap,FAS system,nicotinamide mononucleotide adenylyl transferase 2,Digit3 and Sarm1),immunomodulation(i.e.,Crry,C3 complement),modulation of neuroinflammation(i.e.,e rythropoietin),reduction of excitotoxicity(i.e.,Com KIlα)and transcription regulation(i.e.,Max,Nrf2).On the other hand,some of gene therapy studies focus on lowering intra ocular pressure,by impacting genes involved in both,decreasing aqueous humor production(i.e.,aquaporin 1),and increasing outflow facility(i.e.,COX2,prostaglandin F2a receptor,RhoA/RhoA kinase signaling pathway,MMP1,Myocilin).The goal of this review is to summarize the current stateof-art and the direction of development of gene therapy strategies for glaucomatous neuropathy.

Facing ethical concerns in the age of precise gene therapy:Outlook on inherited arrhythmias

This editorial,comments on the article by Spartalis et al published in the recent issue of the World Journal of Cardiology.We here provide an outlook on potential ethical concerns related to the future application of gene therapy in the field of inherited arrhythmias.As monogenic diseases with no or few therapeutic options available through standard care,inherited arrhythmias are ideal candidates to gene therapy in their treatment.Patients with inherited arrhythmias typically have a poor quality of life,especially young people engaged in agonistic sports.While genome editing for treatment of inherited arrhythmias still has theoretical application,advances in CRISPR/Cas9 technology now allows the generation of knock-in animal models of the disease.However,clinical translation is somehow expected soon and this make consistent discussing about ethical concerns related to gene editing in inherited arrhythmias.Genomic off-target activity is a known technical issue,but its relationship with ethnical and individual genetical diversity raises concerns about an equitable accessibility.Meanwhile,the costeffectiveness may further limit an equal distribution of gene therapies.The economic burden of gene therapies on healthcare systems is is increasingly recognized as a pressing concern.A growing body of studies are reporting uncertainty in payback periods with intuitive short-term effects for insurance-based healthcare systems,but potential concerns for universal healthcare systems in the long term as well.Altogether,those aspects strongly indicate a need of regulatory entities to manage those issues.

Construction of Bifidobacterium Infantis/CD Targeting Gene Therapy System

Objective： To construct Bifidobacterium Infantis/CD targeting gene therapy system. Methods： CD gene was amplified from E. Coli K12λ using PCR method, pGEX-1LamdaT plasmid and CD gene were digested with dual restriction endonucleas of EcoR Ⅰ and BamH Ⅰ and two segments of 4.9 kb and 1.3 kb were obtained. T4 DNA ligase was added to these two segments to make a recombinant CD/pGEX-1LamdaT plasmid. Then the recombinant plasmid was transfected into Bifidobacterium Infantis by electroporation. The recombinant plasmid was extracted from the positively transfected Bifidobacterium Infantis and digested with dual restriction endonucleases. Then the size of digested fragments was detected and sequencing of the gene segment inserted in extracted recombinant plasmid was performed according to the method of Sanger dideoxynucleotide triphosphate chain termination. Results： 6.2 kb recombinant plasmid was obtained from the positively transfected bacterial colony of Bifidobacterium Infantis. After being digested with dual restriction endonucleases, two segments of approximate 4.9 kb and 1.3 kb were gained from the extracted recombinant plasmid, which were equal to the size of pGEX-1LamdaT plasmid and CD gene, respectively. The full length and sequence of nucleotide acid of the inserted gene in extracted recombinant plasmid was completely identical to the CD gene. Conclusion： The foreign gene, CD gene was correctly inserted into pGEX-1LambdaT plasmid and transferred into Bifidobacterium Infantis. Bifidobacterium Infantis/CD targeting gene therapy system was successfully constructed.

Presymptomatic Diagnosis and Gene Therapy for Alzheimer’s Disease: Genomic, Therapeutic, and Ethical Aspects—A Systematic Review

Over the past three decades, genomic and epigenetic sciences have identified more than 70 genes involved in the molecular pathophysiology of Alzheimer’s disease (AD). DNA methylation, abnormal histone and chromatin regulation and the action of various miRNAs induce AD. The identification of mutated genes has paved the way for the development of diagnostic kits and the initiation of gene therapy trials. However, despite major advances in neuroscience research, there is yet no suitable treatment for AD. Therefore, the early diagnosis of this neurodegenerative disease raises several ethical questions, including the balance between the principle of non-maleficence and the principle of beneficence. The aims of this research were to present the genomic and ethical aspects of AD, and to highlight the ethical principles involved in its presymptomatic diagnosis and therapy. A systematic review of the literature in PubMed, Google Scholar and Science Direct was carried out to outline the genomic aspects and ethical principles relating not only to the presymptomatic diagnosis of AD, but also to its gene therapy. A total of 16 publications were selected. AD is a multifactorial disease that can be genetically classified into Sporadic Alzheimer’s Disease and Familial Alzheimer’s Disease based on family history. Gene therapy targeting specific disease-causing genes is a promising therapeutic strategy. Advancements in artificial intelligence applications may enable the prediction of AD onset several years in advance. While early diagnosis of AD may empower patients with full decision competence for early decision-making, it also carries implications for the patient’s family members, who are at risk of developing the disease, potentially becoming a source of confusion or anxiety. AD has a significant impact on the life of individuals at risk and their families. Given the absence of disease modifying therapy, genetic screening and early diagnosis for this condition raise ethical issues that must be carefully considered in the context of fundamental bioethical principles, including autonomy, beneficence, non-maleficence, and justice.

Gene therapy for Parkinson’s Disease and Ethical Challenges: A Systematic Review

Background: Parkinson’s disease (PD) is a complex, multifactorial neurodegenerative disorder with a pathophysiology deriving from the synergy of abnormal aggregation of neuroinflammation, synuclein and dysfunction of lysosomes, mitochondria and synaptic transport difficulties influenced by genetic and idiopathic factors. Worldwide, PD has a prevalence of 2-3% in people over the age of 65. To date, there is no certified, effective treatment for PD. Aim: The aims of this research were: (i) to present, on the basis of recent advances in molecular genetics and epigenetics, the genomic aspects and challenges of gene therapy trials for PD;(ii) to outline the ethical principles applicable to therapeutic trials for PD. Method: A systematic literature review was carried out to identify relevant articles reporting on genomic aspects and gene therapy in PD from 2001 to October 2023. The search was conducted in French and/or English in three databases: PubMed, Google Scholar and Science Direct. PRISMA guidelines were used in this systematic review. Results: A total of thirty-three publications were selected. An inductive thematic analysis revealed that numerous genetic mutations (SNCA, Parkin, PINK1, DJ-1, LRRK2, ATP13A2, VPS35, Parkin/PRKN, PINK1, DJ1/PARK7) and epigenetic events such as the action of certain miRNAs (miR-7, miR-153, miR-133b, miR-124, miR-137) are responsible for the onset of PD, and that genetic therapy for this pathology raises ethical questions that need to be elucidated in the light of the bioethical principles of autonomy, beneficence, non-maleficence and justice. Conclusion: There is no zero risk in biotechnology. Then, it will be necessary to assess all the potential risks of Parkinson disease’s gene therapy to make the right decision. It is therefore essential to pursue research and, with the guidance of ethics, to advance treatment options and meet the challenges of brain manipulation and its impact on human identity. The golden rule of medicine remains: “Primum non nocere”.

Advances in gene therapy of liver cirrhosis: a review

INTRODUCTIONLiver fibrosis or cirrhosis is a common progressively pathological lesion of chronic liver diseases in response to various liver-damaging factors. The main mechanisms of fibrotic or cirrhotic initiation and progression at the level of cellular and molecular events have been elucidated in the past two decades[1,2].

Improvement in erectile dysfunction after insulin-like growth factor-1 gene therapy in diabetic rats

Aim： To determine whether adenoviral gene transfer of insulin like growth factor-1 （IGF-1） to the penis of streptozotocin （STZ）-induced diabetic rats could improve erectile capacity. Methods： The STZ diabetic rats were transfected with AdCMV-βgal or AdCMV-IGF-1. These rats underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age-matched control rats 1 to 2 days after transfection. In control and transfected STZ diabetic rats, IGF-1 expression were examined by reverse transcription polymerase chain reaction （RT-PCR）, Western blot and histology. The penis β-galactosidase activity and localization of the STZ diabetic rats were also determined. Results： One to two days after transfection, the β-galactosidase was found in the smooth muscle cells of the diabetic rat penis transfected with AdCMV-βgal. One to 2 days after administration of AdCMV- IGF-1, the cavernosal pressure, as determined by the ratio of maximal intracavernous pressure-to-mean arterial pressure （ICP/MAP） and total intracavernous pressure （ICP）, was increased in response to cavernous nerve stimulation. Transgene expression was confirmed by RT-PCR, Western blot and histology. Conclusion： Gene transfer of IGF-1 significantly increased erectile function in the STZ diabetic rats. These results suggest that in vivo gene transfer of IGF- 1 might be a new therapeutic intervention for the treatment of erectile dysfunction （ED） in the STZ diabetic rats.

Adenoviral gene therapy in gastric cancer: A review

Gastric cancer is one of the most common malignancies worldwide. With current therapeutic approaches the prognosis of gastric cancer is very poor, as gastric cancer accounts for the second most common cause of death in cancer related deaths. Gastric cancer like almost all other cancers has a molecular genetic basis which relies on disruption in normal cellular regulatory mechanisms regarding cell growth, apoptosis and cell division. Thus novel therapeutic approaches such as gene therapy promise to become the alternative choice of treatment in gastric cancer. In gene therapy, suicide genes, tumor suppressor genes and anti-angiogenesis genes among many others are introduced to cancer cells via vectors. Some of the vectors widely used in gene therapy are Adenoviral vectors. This review provides an update of the new developments in adenoviral cancer gene therapy including strategies for inducing apoptosis, inhibiting metastasis and targeting the cancer cells.

p53 gene therapy in combination with transcatheter arterial chemoembolization for HCC:One-year follow-up

AIM:To evaluate the efficacy and safety of combination therapy with recombinant adenovirus p53 injection (rAdp53) and transcatheter hepatic arterial chemoembolization (TACE) for advanced hepatocellular carcinoma (HCC).METHODS:A total of 82 patients with advanced HCC treated only with TACE served as control group.Another 68 patients with HCC treated with TACE in combination with recombinant adenovirus-p53 injection served as p53 treatment group.Patients were followed up for 12 mo.Safety and therapeutic effects were evaluated according to the improvement in clinical symptoms,leukocyte count,Karnofsky and RECIST criteria.Survival rate was calculated with Kaplan-Meier method.RESULTS:The total effective rate was 58.3% for p53 treatment group,and 26.5% for control group (P < 0.05).The incidence of gastrointestinal symptoms was lower in p53 treatment group than in control group (P < 0.05).The 3-,6-and 12-mo survival rates were significantly higher for p53 treatment group than for control group (P < 0.01).The combination treatment was well tolerated with such adverse events as fever (51.5%,P=0.006) and pain of muscles and joints (13.2%,P=0.003),which were significantly higher than the chemotherapy.Except for these minor adverse effects,no severe vector-related complications were identified.With respect to the efficacy,patients in p53 treatment group had less gastrointerestinal symptoms (P=0.062),better improvement in tumor-related pain (P=0.003),less downgrade of leukocyte counts (P=0.003) and more upgrade of Karnofsky performance score (P=0.029) than those in control group.The total effective rate (CR + PR) for p53 treatment group and control group was 58.3% and 26.5%,respectively,with distributions of different effect in two groups (P=0.042).The survival rates were 89.71%,76.13%,and 43.30% for p53 treatment group,and 68.15%,36.98%,and 24.02% for control group,respectively,3,6 and 12 mo after treatment,suggesting that the survival rates are significantly higher for p53 treatment group than for control group (P=0.0002).CONCLUSION:The rAd-p53 gene therapy in combination with TACE is a safe and effective treatment modality for advanced HCC.

Therapy of cancer by cytokines mediated by gene therapy approach

Gene therapy offers a new approach for treatment of cancer. Transfer of genes encoding immunostimulatory cytokines has been used with remarkable success to eliminate cancer in animals. However, clinical trials in patients with this strategy had limited efficacy. Therefore, improvement ofgene transfer vector system is necessary. A hybrid viral vector, consisting of SFV replicon with either murine IL-12 or reporter LacZ gene, was constructed. This hybrid vector showed specificity and high level of expression in HCC both in vitro and in vivo. In a rat orthotropic liver tumor model, treatment of established tumors by the hybrid vector with raiL- 12 gene resulted in a strong anti-tumor activity without accompanying toxicity. Subsequently, a helper-dependent adenovirus vectors containing a mifepristone （RU486） inducible system was constructed for controlled and liver-specific expression of human interleukin 12 （hIL- 12） （HD-Ad/RUhIL- 12） and mouse IL-12 （mIL-12） （HD-Ad/RUmIL-12）. Data showed that high and sustained serum levels of hlL-12 could be attained by continuing administration of RU486 every 12 or 24 h. Repetitive induction ofhlL-12 could be obtained over, at least, a period of 48 weeks after a single injection of HD-Ad/RUhlL-12. Treatment of liver metastases with of HD-Ad/RUmIL- 12 plus RU846 resulted in complete tumor regression in all animals. Then, different cytokine genes were inserted into conditional replicative adenoviruses vectors （also called oncolytic adenovirus）. Replication ofadenovirus in tumor cells would kill tumor cells and release viruses, which infect surrounding tumor cells. The combination of cytopathic effect by oncolytic adenovirus and biological effect of transgene would exert strong antitumor activity. These new types of vectors may provide a potent and safe tool for cancer gene therapy.

Current gene therapy for stomach carcinoma

Gastric cancer is common in China [1-42],and its early diagnosis and treatment in advanced stage are difficult [31-50].In recent years ,gene study in cancer is a hotspot ,and great progress has been achieved [41-80] .Cancer gene therapy has shifted from the imagination into the laboratory and clinical trials.

Reduction of tumorigenicity of SMMC-7721 hepatoma cells by vascular endothelial growth factor antisense gene therapy

AIM: To test the hypothesis to block VEGF expression of SMMC-7721 hepatoma cells may inhibit tumor growth using the rat hepatoma model. METHODS: Amplify the 200 VEGF cDNA fragment and insert it into human U6 gene cassette in the reverse orientation transcribing small antisense RNA which could specifically interact with VEGF165, and VEGF121 mRNA. Construct the retroviral vector containing this antisense VEGF U6 cassette and package the replication-deficient recombinant retrovirus. SMMC-7721 cells were transduced with these virus and positive clones were selected with G418. PCR and Southern blot analysis were performed to determine if U6 cassette integrated into the genomic DNA of positive clone. Transfected tumor cells were evaluated for RNA expression by ribonuclease protection assays. The VEGF protein in the supernatant of parental tumor cells and genetically modified tumor cells was determined with ELISA. In vitro and in vivo growth properties of antisense VEGF cell clone in nude mice were analyzed. RESULTS: Restriction enzyme digestion and PCR sequencing verified that the antisense VEGF RNA retroviral vector was successfully constructed.After G418 selection, resistant SMMC-7721 cell clone was picked up. PCR and Southern blot analysis suggested that U6 cassette was integrated into the cell genomic DNA. Stable SMMC-7721 cell clone transduced with U6 antisense RNA cassette could express 200 bp small antisense VEGF RNA and secrete reduced levels of VEGF in culture condition. Production of VEGF by antisense transgene-expressing cells was 65+/-10 ng/L per 10(6) cells, 42045 ng/L per 10(6) cells in sense group and 485+/-30 ng/L per 10(6) cells in the negative control group, (P【 0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S.C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells. CONCLUSION: Expression of antisense VEGF RNA in SMMC-7721 cells could decrease the tumorigenicity, and antisense-VEGF gene therapy may be an adjuvant treatment for hepatoma.

Prevention of peritoneal adhesions:A promising role for gene therapy

Adhesions are the most frequent complication of abdominopelvic surgery,yet the extent of the problem,and its serious consequences,has not been adequately recognized.Adhesions evolved as a life-saving mecha-nism to limit the spread of intraperitoneal inflammatory conditions.Three different pathophysiological mechanisms can independently trigger adhesion formation.Mesothelial cell injury and loss during operations,tissue hypoxia and inflammation each promotes adhesion formation separately,and potentiate the effect of each other.Studies have repeatedly demonstrated that interruption of a single pathway does not completely prevent adhesion formation.This review summarizes the pathogenesis of adhesion formation and the results of single gene therapy interventions.It explores the prom-ising role of combinatorial gene therapy and vector modif ications for the prevention of adhesion formation in order to stimulate new ideas and encourage rapid advancements in this field.

Keratinocyte growth factor gene therapy ameliorates ulcerative colitis in rats

AIM:To investigate the effect of keratinocyte growth factor(KGF) gene therapy in acetic acid-induced ulcerative colitis in rat model.METHODS:The colitis of Sprague-Dawley rats was induced by intrarectal infusion of 1 mL 5%(v/v) acetic acid.Twenty-four hours after exposed to acetic acid,rats were divided into three experimental groups:control group,attenuated Salmonella typhimurium Ty21a strain(SP) group and SP strain carrying human KGF gene(SPK) group,and they were separately administered orally with 10% NaHCO3,SP or SPK.Animals were sacrificed and colonic tissues were harvested respectively on day 3,5,7 and 10 after administration.Weights of rats,colonic weight/length ratio and stool score were evaluated.Histological changes of colonic tissues were examined by hematoxylin and eosin(HE) staining method.The expression of KGF,KGF receptor(KGFR) and TNF-α were measured either by enzyme-linked immunosorbent assay or Western blotting.Immunohistochemistry was used to detect the cellular localization of KGFR and Ki67.In addition,superoxide dismutase(SOD) activity and malondialdehyde(MDA) contents in the homogenate were measured.RESULTS:Body weight and colonic weight/length ratio were declined in SPK group compared with SP and control groups(body weight:272.78 ± 17.92 g vs 243.72 ± 14.02 g and 240.68 ± 12.63 g,P < 0.01;colonic weight/length ratio:115.76 ± 7.47 vs 150.32 ± 5.99 and 153.67 ± 5.50 mg/cm,P < 0.01).Moreover,pathological changes of damaged colon were improved in SPK group as well.After administration of SPK strain,KGF expression increased markedly from the 3rd d,and remained at a high level till the 10th d.Furthermore,KGFR expression and Ki67 expression elevated,whereas TNF-α expression was inhibited in SPK group.In the group administered with SPK,SOD activity increased significantly(d 5:26.18 ± 5.84 vs 18.12 ± 3.30 and 18.79 ± 4.74 U/mg,P < 0.01;d 7:35.48 ± 3.35 vs 22.57 ± 3.44 and 21.69 ± 3.94 U/mg,P < 0.01;d 10:46.10 ± 6.23 vs 25.35 ± 4.76 and 27.82 ± 6.42 U/mg,P < 0.01) and MDA contents decreased accordingly(d 7:7.40 ± 0.88 vs 9.81 ± 1.21 and 10.45 ± 1.40 nmol/mg,P < 0.01;d 10:4.36 ± 0.62 vs 8.41 ± 0.92 and 8.71 ± 1.27 nmol/mg,P < 0.01),compared with SP and control groups.CONCLUSION:KGF gene therapy mediated by attenuated Salmonella ameliorates ulcerative colitis induced by acetic acids,and it may be a safe and effective treatment for ulcerative colitis.

Combinational adenovirus-mediated gene therapy and dendritic cell vaccine in combating well-established tumors

Recent developments in tumor immunology and biotechnology have made cancer gene therapy and immunotherapy feasible. The current efforts for cancer gene therapy mainly focus on using immunogenes, chemogenes and tumor suppressor genes. Central to all these therapies is the development of efficient vectors for gene therapy. By far, adenovirus （AdV）-mediated gene therapy is one of the most promising approaches, as has confirmed by studies relating to animal tumor models and clinical trials. Dendritic cells （DCs） are highly efficient, specialized antigen-presenting cells, and DC- based tumor vaccines are regarded as having much potential in cancer immunotherapy. Vaccination with DCs pulsed with tumor peptides, lysates, or RNA, or loaded with apoptotic/necrotic tumor cells, or engineered to express certain cytokines or chemokines could induce significant antitumor cytotoxic T lymphocyte （CTL） responses and antitumor immunity. Although both AdV-mediated gene therapy and DC vaccine can both stimulate antitumor immune responses, their therapeutic efficiency has been limited to generation of prophylactic antitumor immunity against re-challenge with the parental tumor cells or to growth inhibition of small tumors. However, this approach has been unsuccessful in combating well-established tumors in animal models. Therefore, a major strategic goal of current cancer immunotherapy has become the development of novel therapeutic strategies that can combat well-established tumors, thus resembling real clinical practice since a good proportion of cancer patients generally present with significant disease. In this paper, we review the recent progress in AdV-mediated cancer gene therapy and DC-based cancer vaccines, and discuss combined immunotherapy including gene therapy and DC vaccines. We underscore the fact that combined therapy may have some advantages in combating well-established tumors vis-a-vis either modality administered as a monotherapy.

Gene therapy of liver cancer

The application of gene transfer technologies to the treatment of cancer has led to the development of new experimental approaches like gene directed enzyme/pro- drug therapy (GDEPT), inhibition of oncogenes and restoration of tumor-suppressor genes. In addition, gene therapy has a big impact on other fields like cancer immunotherapy, anti-angiogenic therapy and virotherapy. These strategies are being evaluated for the treatment of primary and metastatic liver cancer and some of them have reached clinical phases. We present a review on the basis and the actual status of gene therapy approaches applied to liver cancer.

Engineered targeting tLyp-1 exosomes as gene therapy vectors for efficient delivery of siRNA into lung cancer cells

Natural exosomes can express specific proteins and carbohydratemolecules on the surface and hence have demonstrated the great potentials for gene therapy of cancer.However,the use of natural exosomes is restricted by their low transfection efficiency.Here,we report a novel targeting tLyp-1 exosome by gene recombinant engineering for delivery of siRNA to cancer and cancer stem cells.To reach such a purpose,the engineered tLyp-1-lamp2b plasmids were constructed and amplified in Escherichia coli.The tLyp-1-lamp2b plasmids were further used to transfect HEK293T tool cells and the targeting tLyp-1 exosomes were isolated from secretion of the transfected HEK293T cells.Afterwards,the artificially synthesized siRNA was encapsulated into targeting tLyp-1 exosomes by electroporation technology.Finally,the targeting siRNA tLyp-1 exosomes were used to transfect cancer or cancer stem cells.Results showed that the engineered targeting tLyp-1 exosomes had a nanosized structure(approximately 100 nm)and high transfection efficiency into lung cancer and cancer stem cells.The function verifications demonstrated that the targeting siRNA tLyp-1 exosomes were able to knock-down the target gene of cancer cells and to reduce the stemness of cancer stem cells.In conclusion,the targeting tLyp-1 exosomes are successfully engineered,and can be used for gene therapy with a high transfection efficiency.Therefore,the engineered targeting tLyp-1 exosomes offer a promising gene delivery platform for future cancer therapy.

Gene therapy for gastric cancer:Is it promising?

Gastric cancer is one of the most common tumors worldwide. The therapeutic outcome of conventional therapies is inefficient. Thus, new therapeutic strategies are urgently needed. Gene therapy is a promising molecular alternative in the treatment of gastric cancer, including the replacement of defective tumor suppressor genes, the inactivation of oncogenes, the introduction of suicide genes, genetic immunotherapy, anti-angiogenetic gene therapy, and virotherapy. Improved molecular biological techniques and a better understanding of gastric carcinogenesis have allowed us to validate a variety of genes as molecular targets for gene therapy. This review provides an update of the new developments in cancer gene therapy, new principles, techniques, strategies and vector systems, and shows how they may be applied in the treatment of gastric cancer.

The Role of β3-adrenergic Receptor Gene in Neuropeptide Y Y5Receptor Antisense Gene Therapy of Diet-induced Obese Rats

Objective: To study the role of β3-adrenergic receptor gene in neuropeptide Y(NPY) Y5 receptor antisense gene therapy of diet-induced obese rats.Methods: The diet-induced obese rats were prepared by feeding a high-nutrition diet. Lateral ventricular was cannulated in obese rats which then received an intraventricular injection of either 5 μg/μl NPY Y5 receptor antisense or 10 μl missense oligodeoxynucleotide or saline of 10 μl respectively in every rat. When the rats were killed, the wet weight of abdominal adipose tissue, the level of serum lipid and lipoprotein were measured. Total RNA from the retroperitoneal adipose tissue was extracted and the level of β3-adrenergic receptor gene mRNA expression was evaluated by RT-PCR.Results: ①The wet weight of abdominal adipose tissue, the levels of serum lipids were greatly higher in diet-induced obese rats than those in normal rats. However, there were much lower β3-adrenergic receptor gene mRNA expression levels in retroperitoneal adipose tissue in diet-induced obese rats as compared with those in normal rats. ②After the diet-induced obese rats were intraventricularly administered with NPY Y5 receptor antisense oligodeoxynucleotide, the levels of β3-adrenergic receptor gene mRNA expression in retroperitoneal adipose tissue of diet-induced obese rats were strikingly up-regulated, whereas the wet weight of abdominal adipose tissue, the levels of serum lipids were markedly reduced.Conclusion: Intraventricular administration of antisense oligodeoxynucleotide to NPY Y5 receptor could significantly reduce the abdominal adipose tissue and the levels of serum lipids in diet-induced obese rats by up-regulating the level of β3-adrenergic receptor gene mRNA expression in retroperitoneal adipose tissue.