AIM：To compare the effectiveness between multiple intravitreal injections of ganciclovir alone and combined with foscarnet as initial treatment for patients with newlyonset cytomegalovirus retinitis （CMVR）.METHODS...AIM：To compare the effectiveness between multiple intravitreal injections of ganciclovir alone and combined with foscarnet as initial treatment for patients with newlyonset cytomegalovirus retinitis （CMVR）.METHODS：The retrospective study observed 37 patients（58 eyes） who suffered from CMVR onset between 2013 and 2015. Among them, 35 eyes underwent 4 weekly intravitreal injections of 3.0 mg ganciclovir, and 23 eyes underwent 4 weekly injections of 3.0 mg ganciclovir combined with 2.4 mg foscarnet. Visual acuity, intraocular pressure and viral load of cytomegalovirus （CMV） in aqueous humor measured by real-time polymerase chain reaction were compared before and after each injection.RESULTS：CMV-DNA copies in aqueous humor decreased remarkably in both groups. The average of CMV-DNA copies in patients’ aqueous decreased from 38.3×10~4 copies/mL at baseline to 2.2×10~4 copies/mL after the 4^（th） injection in patients who were treated with ganciclovir monotherapy,and decreased from 76.9×10~4 copies/mL to 11.3×10~4 copies/mL after 4 continuous injections of ganciclovir combined with foscarnet. No significant difference was found in reduction of viral load, change of visual acuities or intraocular pressures between monotherapy or combined therapy.CONCLUSION：Results of this study show that the initial effectiveness of treating CMVR after 4 weekly intravitreal injections is not significantly different from ganciclovir alone or combined with foscarnet. Continuous injection of ganciclovir alone is sufficient in treating immunosuppressive patients with newly-onset CMVR.展开更多
The effect of intravitreal ganciclovir injection combined with intravenous infusion on acquired immune deficiency syndrome(AIDS) patients with cytomegalovirus retinitis(CMVR) was investigated. A total of 32 eyes in 23...The effect of intravitreal ganciclovir injection combined with intravenous infusion on acquired immune deficiency syndrome(AIDS) patients with cytomegalovirus retinitis(CMVR) was investigated. A total of 32 eyes in 23 AIDS patients diagnosed as CMVR from 2017 to 2018 were included in the retrospective study. All patients underwent induction therapy by using intravenous drip of the anticytomegalovirus(CMV) agent ganciclovir(5 mg/kg q12 h) combined with intravitreal ganciclovir injection(3 mg/time, 2 times/wk). The visual acuity, fundus photographs, lesion location, and number of intravitreal injections were observed preoperatively and postoperatively. Totally 14 eyes were cured during induction therapy. The number of injections [4.13(2 to 6)] in CMVR patients with peripherally fundus lesions were significantly lower than those with central lesions (4.89(2 to 6))The individualized therapy of intravitreal ganciclovir injections for AIDS patients with CMVR can effectively reduce the numbers of intravitreal injections.展开更多
Cytomegalovirus(CMV) infection is associated with adverse clinical outcomes in immunosuppressed persons.The incidence and association of CMV reactivation with adverse clinical outcomes in critically ill persons lackin...Cytomegalovirus(CMV) infection is associated with adverse clinical outcomes in immunosuppressed persons.The incidence and association of CMV reactivation with adverse clinical outcomes in critically ill persons lacking evidence of immunosuppression at ICU admission has received great attention in the practice of critical care medicine.Critically ill patients in ICU who had associated risk factors such as mechanical ventilation,severe sepsis, or blood transfusion are more prone to CMV activation,which in turn led to increased mortality and morbidity in tenns of increased ICU stay,longer duration of mechanical ventilation,and higher rates of nosocomial infections.However,severe CMV as initial presentation mimicking dengue infection is rare.We recently came across seven cases with positive CMV serology at ICU admission,which we discuss in the light of current literature.展开更多
Objective High performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC/MS)methods were developed for the determination of ganciclovir and its related substances.Methods A Hypersil ODS2 co...Objective High performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC/MS)methods were developed for the determination of ganciclovir and its related substances.Methods A Hypersil ODS2 column(4.6 mm×250 mm,5 μm)was used with a mobile phase of 0.02 M potassium dihydrogen phosphate buffer(pH 6.0)-methanol(92∶8)at a flow rate of 1.0 mL/min,and UV detector set at 254 nm was used for monitoring the eluents.Results The method was simple,rapid,selective and capable of separating all related substances at trace level with a detection limit of 0.04 μg/mL.It has been validated with respect to accuracy,precision,linearity,and limits of detection and quantification.The linearity range was 10.2-153.0 μg/mL with r=0.9998.The percentage recoveries ranged from 96.7% to 101.6%,and RSD was 1.24%-1.96%(n=5).Conclusion The method was found to be suitable not only for monitoring the reactions during the process development but also for quality control of ganciclovir.For identification of related substances,LC/MS was used.The mainly related substances of ganciclovir active pharmaceutical ingredients(API)were determined as guanine,(1,3-dioxolan-4-yl)methyl acetate,and diacetyl guanine.展开更多
Objective:Cytopathic effects and local immune response were analyzed histologically in prostatic cancer(PCa)with in situ herpes simplex virus-thymidine kinase(HSV-tk)/ganciclovir(GCV)gene therapy(GT).Methods:Four high...Objective:Cytopathic effects and local immune response were analyzed histologically in prostatic cancer(PCa)with in situ herpes simplex virus-thymidine kinase(HSV-tk)/ganciclovir(GCV)gene therapy(GT).Methods:Four high-risk PCa patients who received HSV-tk/GCV GT were investigated.After two cycles of intraprostatic injection of HSV-tk and administration of GCV,radical prostatectomy was performed.Formalin-fixed,paraffin-embedded sections were evaluated using immunohistochemistry.PCa with hormone therapy(HT,n=3)or without neoadjuvant therapy(NT,n=4)that were equivalent in terms of risk were also examined as reference.Immunoreactively-positive cells were counted in at least three areas in cancer tissue.Labeling indices(LI)were calculated as percentage values.Results:ssDNA LI in GT increased,indicating apoptosis,as well as tumor-infiltrating lymphocytes and CD68-positive macrophages,compared with their biopsies.GT cases showed significantly higher numbers of single-stranded DNA(ssDNA)LI,CD4/CD8-positive T cells and CD68-positive macrophages including M1/M2 macrophages than HT or NT cases.However,there was no significant difference in CD20-positive B cells among the types of case.There were strong correlations between CD8+T cells and CD68+macrophages(ρ=0.656,p<0.0001)as well as CD4+T cells and CD20+B cells(ρ=0.644,p<0.0001)in PCa with GT.Conclusions:Enhanced cytopathic effect and local immune response might be indicated in PCa patients with HSV-tk/GCV gene therapy.展开更多
The killing effects of herpes simplex virus thymidine kinase gene/ganciclovir （HSV-tk/GCV） approach by the addition of several commonly clinical chemotherapeutic agents on hormone refractory prostate cancer （HRPC）...The killing effects of herpes simplex virus thymidine kinase gene/ganciclovir （HSV-tk/GCV） approach by the addition of several commonly clinical chemotherapeutic agents on hormone refractory prostate cancer （HRPC） cells PC-3m were investigated. After transferring of the HSV-tk gene into PC-3m cells, mRNA and protein expression of HSV-tk was detected by reverse-transcript polymerase chain reaction （RT-PCR） and strept avidin-biotin complex （SABC） im- munohistochemical method. The killing effect of GCV, cisplatin （CDDP）, etoposide （VP-16）, vincristine （VCR）, methotrexate （MTX）, 5-fluorouracil （5-Fu）, and suramin on PC-3m cells was evaluated by morphological assessment analysis, trypan blue exclusion assay and MTT assay respectively. Additionally, the cooperative effect of HSV-tk/GCV system combined with the above agents on the target cancer cells was determined by MTT. Furthermore, apoptosis and necrosis induced by GCV plus 5-Fu or suramin was analyzed by flow cytometry （FCM）. The results showed that that there was HSV-tk mRNA and protein expression in pDR2-tk plasmid transduced PC-3m cell. Combination of GCV with VP-16, VCR, 5-Fu or suramin led to an enhanced cellular killing effect, but with CDDP resulted in a reduced one and with MTX in an approximate one. FCM revealed that synergistic use of GCV and 5-fu or suramin resulted in a rather large proportion of apoptosis and necrosis with the apoptosis index being 36.38 % and 35.51%, and the proportion of necrosis being 33.05 % and 28.87 %, respectively. In conclusion, HSV-tk/CGV approach by addition of certain clinical available chemotherapeutic drugs brings on statistically significant enhanced cell killing over single-agent treatment. Our results highlight the potential for such new combination therapies for future treatments of HRPC.展开更多
Background：Herpes simplex keratitis （HSK） caused by herpes simplex virus 1 （HSV-1）,which has high recurrent rate and incidence of severe vision loss,is the leading cause of infectious blindness in the world.The a...Background：Herpes simplex keratitis （HSK） caused by herpes simplex virus 1 （HSV-1）,which has high recurrent rate and incidence of severe vision loss,is the leading cause of infectious blindness in the world.The aim was to explore the clinical efficacy of oral ganciclovir （GCV） in the prevention of recurrent HSK.Methods：A multicenter,prospective,randomized,single-blind,and controlled clinical trial was conducted from April 2010 to June 2013.One hundred seventy-three patients （173 eyes involved） who were diagnosed as recurrent HSK definitely,including stromal keratitis and corneal endotheliitis,were divided into three groups randomly：negative control （placebo） group was topically administered with 0.15% GCV ophthalmic gel,4 times per day and 0.1% fluorometholone eye drops,3 times per day until resolution of HSK; positive control acyclovir （ACV） group was topically adopted the same ophthalmic gel and eye drops and additionally received oral ACV 400 mg 5 times a day for 10 weeks and followed by 400 mg 2 times per day for 6 months; test GCV group was topically adopted the same treatment as negative control group and additionally received oral GCV 1000 mg 3 times per day for 8 weeks.The symptoms and signs were evaluated before and after the therapy 1^st week,2^nd week and then followed up every 2 weeks until recovery.Furthermore,we followed up recurrence of HSK for every 3 months after recovery and then assessed the cure time,recurrent rate and adverse reactions.Results：One hundred and seventy-three patients were followed up 7-48 months （mean 32.1 ± 12.3 months）,but 34 patients were failed to follow-up.The cure time was 12.1± 4.3,11.9 ± 4.0 weeks in negative control （placebo） group and positive control ACV group respectively （P =0.991）,which was longer than that in test GCV group （8.6 ± 2.8 weeks） and there was a significant difference between test GCV group and negative control （placebo） group or positive control ACV group （P =0.000）.Furthermore,the recurrent rate was higher in negative control （placebo） group （47.3%） than that in positive control group ACV （26.7%） and test GCV group （17.2%）,and there was a great significant difference among the three groups （P =0.007）,but there was no significant difference between positive control ACV group and test GCV group （P =0.358）.In addition,there was no obvious adverse reaction expect neutropenia （only one patient in test GCV group）.Conclusion：Short-term oral GCV could cure recurrent HSK and endotheliitis,shorten the course,reduce recurrent rate of HSK and have confirmed safety.展开更多
Background Herpes simplex virus thymidine kinase phosphorylates ganciclovir to ganciclovir monophosphate,which is then converted to ganciclovir triphosphate by endogenous cellular nucleoside kinases.The ganciclovir tr...Background Herpes simplex virus thymidine kinase phosphorylates ganciclovir to ganciclovir monophosphate,which is then converted to ganciclovir triphosphate by endogenous cellular nucleoside kinases.The ganciclovir triphosphate acts as a DNA chain terminator due to the lack of a functional 3＇-OH group and terminates the process of DNA replication,hence leading to cell apoptosis.At present,HSVtk gene usually acts as suicide gene to kill tumor cells.The aim of this study was to investigate the selective cytotoxicity of the herpes simplex virus thymidine kinase/ganciclovir （HSVtK/GCV） suicide gene system controlled by the α-fetoprotein （AFP） promoter on hepatocellular carcinoma （HCC） cells in vitro.Methods pAFP-HSVtk-IRES2-EGFP recombinant plasmid vectors driven by the AFP promoter were constructed.HL-7702 liver cells,HUH-7 HCC,and HepG2 HCC were transfected with the recombinant plasmids.HSVtK gene expression was detected using Western blotting analysis.HepG2 cells line stably expressing HSVtk gene was selected by G418 reagent.The cytotoxicity of HSVtK/GCV suicide gene system on hepatoma cells was measured by CCK-8 reagents when different doses of ganciclovir were added.Results Plasmid pAFP-TK-IRES2-EGFP-expressed HSVtk gene was constructed successfully.HSVtk gene expression level was significantly higher in AFP-positive hepatoma cells than in AFP-negative liver cells.After G418 selection,a HepG2 cells line stably expressing HSVtk gene was acquired.With the increase of the dose of ganciclovir the optical density at 450 nm of HepG2 cells stably expressing HSVtk gene gradually decreased （P ＜0.05）.Conclusion The HSVtK gene-specific expression in hepatoma cells as well as the cytotoxicity of the suicide gene system in HepG2 cells provided the basis for the targeted gene therapy of HCC.展开更多
基金Supported by the 1351 Beijing Chaoyang Talent Training Program(No.CYXX-2017-21)
文摘AIM：To compare the effectiveness between multiple intravitreal injections of ganciclovir alone and combined with foscarnet as initial treatment for patients with newlyonset cytomegalovirus retinitis （CMVR）.METHODS：The retrospective study observed 37 patients（58 eyes） who suffered from CMVR onset between 2013 and 2015. Among them, 35 eyes underwent 4 weekly intravitreal injections of 3.0 mg ganciclovir, and 23 eyes underwent 4 weekly injections of 3.0 mg ganciclovir combined with 2.4 mg foscarnet. Visual acuity, intraocular pressure and viral load of cytomegalovirus （CMV） in aqueous humor measured by real-time polymerase chain reaction were compared before and after each injection.RESULTS：CMV-DNA copies in aqueous humor decreased remarkably in both groups. The average of CMV-DNA copies in patients’ aqueous decreased from 38.3×10~4 copies/mL at baseline to 2.2×10~4 copies/mL after the 4^（th） injection in patients who were treated with ganciclovir monotherapy,and decreased from 76.9×10~4 copies/mL to 11.3×10~4 copies/mL after 4 continuous injections of ganciclovir combined with foscarnet. No significant difference was found in reduction of viral load, change of visual acuities or intraocular pressures between monotherapy or combined therapy.CONCLUSION：Results of this study show that the initial effectiveness of treating CMVR after 4 weekly intravitreal injections is not significantly different from ganciclovir alone or combined with foscarnet. Continuous injection of ganciclovir alone is sufficient in treating immunosuppressive patients with newly-onset CMVR.
基金Supported by the Open Research Project of Key Laboratory of Capital Medical University (No.2017YKSJ04)Capital Medical University Fundamental Clinical Research Cooperation Fund (No.16JL73)
文摘The effect of intravitreal ganciclovir injection combined with intravenous infusion on acquired immune deficiency syndrome(AIDS) patients with cytomegalovirus retinitis(CMVR) was investigated. A total of 32 eyes in 23 AIDS patients diagnosed as CMVR from 2017 to 2018 were included in the retrospective study. All patients underwent induction therapy by using intravenous drip of the anticytomegalovirus(CMV) agent ganciclovir(5 mg/kg q12 h) combined with intravitreal ganciclovir injection(3 mg/time, 2 times/wk). The visual acuity, fundus photographs, lesion location, and number of intravitreal injections were observed preoperatively and postoperatively. Totally 14 eyes were cured during induction therapy. The number of injections [4.13(2 to 6)] in CMVR patients with peripherally fundus lesions were significantly lower than those with central lesions (4.89(2 to 6))The individualized therapy of intravitreal ganciclovir injections for AIDS patients with CMVR can effectively reduce the numbers of intravitreal injections.
文摘Cytomegalovirus(CMV) infection is associated with adverse clinical outcomes in immunosuppressed persons.The incidence and association of CMV reactivation with adverse clinical outcomes in critically ill persons lacking evidence of immunosuppression at ICU admission has received great attention in the practice of critical care medicine.Critically ill patients in ICU who had associated risk factors such as mechanical ventilation,severe sepsis, or blood transfusion are more prone to CMV activation,which in turn led to increased mortality and morbidity in tenns of increased ICU stay,longer duration of mechanical ventilation,and higher rates of nosocomial infections.However,severe CMV as initial presentation mimicking dengue infection is rare.We recently came across seven cases with positive CMV serology at ICU admission,which we discuss in the light of current literature.
文摘Objective High performance liquid chromatography(HPLC)and liquid chromatography-mass spectrometry(LC/MS)methods were developed for the determination of ganciclovir and its related substances.Methods A Hypersil ODS2 column(4.6 mm×250 mm,5 μm)was used with a mobile phase of 0.02 M potassium dihydrogen phosphate buffer(pH 6.0)-methanol(92∶8)at a flow rate of 1.0 mL/min,and UV detector set at 254 nm was used for monitoring the eluents.Results The method was simple,rapid,selective and capable of separating all related substances at trace level with a detection limit of 0.04 μg/mL.It has been validated with respect to accuracy,precision,linearity,and limits of detection and quantification.The linearity range was 10.2-153.0 μg/mL with r=0.9998.The percentage recoveries ranged from 96.7% to 101.6%,and RSD was 1.24%-1.96%(n=5).Conclusion The method was found to be suitable not only for monitoring the reactions during the process development but also for quality control of ganciclovir.For identification of related substances,LC/MS was used.The mainly related substances of ganciclovir active pharmaceutical ingredients(API)were determined as guanine,(1,3-dioxolan-4-yl)methyl acetate,and diacetyl guanine.
基金supported by Grants-in-Aid for Scientific Research(JSPS KAKENHI)grant(number 21592060).
文摘Objective:Cytopathic effects and local immune response were analyzed histologically in prostatic cancer(PCa)with in situ herpes simplex virus-thymidine kinase(HSV-tk)/ganciclovir(GCV)gene therapy(GT).Methods:Four high-risk PCa patients who received HSV-tk/GCV GT were investigated.After two cycles of intraprostatic injection of HSV-tk and administration of GCV,radical prostatectomy was performed.Formalin-fixed,paraffin-embedded sections were evaluated using immunohistochemistry.PCa with hormone therapy(HT,n=3)or without neoadjuvant therapy(NT,n=4)that were equivalent in terms of risk were also examined as reference.Immunoreactively-positive cells were counted in at least three areas in cancer tissue.Labeling indices(LI)were calculated as percentage values.Results:ssDNA LI in GT increased,indicating apoptosis,as well as tumor-infiltrating lymphocytes and CD68-positive macrophages,compared with their biopsies.GT cases showed significantly higher numbers of single-stranded DNA(ssDNA)LI,CD4/CD8-positive T cells and CD68-positive macrophages including M1/M2 macrophages than HT or NT cases.However,there was no significant difference in CD20-positive B cells among the types of case.There were strong correlations between CD8+T cells and CD68+macrophages(ρ=0.656,p<0.0001)as well as CD4+T cells and CD20+B cells(ρ=0.644,p<0.0001)in PCa with GT.Conclusions:Enhanced cytopathic effect and local immune response might be indicated in PCa patients with HSV-tk/GCV gene therapy.
文摘The killing effects of herpes simplex virus thymidine kinase gene/ganciclovir （HSV-tk/GCV） approach by the addition of several commonly clinical chemotherapeutic agents on hormone refractory prostate cancer （HRPC） cells PC-3m were investigated. After transferring of the HSV-tk gene into PC-3m cells, mRNA and protein expression of HSV-tk was detected by reverse-transcript polymerase chain reaction （RT-PCR） and strept avidin-biotin complex （SABC） im- munohistochemical method. The killing effect of GCV, cisplatin （CDDP）, etoposide （VP-16）, vincristine （VCR）, methotrexate （MTX）, 5-fluorouracil （5-Fu）, and suramin on PC-3m cells was evaluated by morphological assessment analysis, trypan blue exclusion assay and MTT assay respectively. Additionally, the cooperative effect of HSV-tk/GCV system combined with the above agents on the target cancer cells was determined by MTT. Furthermore, apoptosis and necrosis induced by GCV plus 5-Fu or suramin was analyzed by flow cytometry （FCM）. The results showed that that there was HSV-tk mRNA and protein expression in pDR2-tk plasmid transduced PC-3m cell. Combination of GCV with VP-16, VCR, 5-Fu or suramin led to an enhanced cellular killing effect, but with CDDP resulted in a reduced one and with MTX in an approximate one. FCM revealed that synergistic use of GCV and 5-fu or suramin resulted in a rather large proportion of apoptosis and necrosis with the apoptosis index being 36.38 % and 35.51%, and the proportion of necrosis being 33.05 % and 28.87 %, respectively. In conclusion, HSV-tk/CGV approach by addition of certain clinical available chemotherapeutic drugs brings on statistically significant enhanced cell killing over single-agent treatment. Our results highlight the potential for such new combination therapies for future treatments of HRPC.
文摘Background：Herpes simplex keratitis （HSK） caused by herpes simplex virus 1 （HSV-1）,which has high recurrent rate and incidence of severe vision loss,is the leading cause of infectious blindness in the world.The aim was to explore the clinical efficacy of oral ganciclovir （GCV） in the prevention of recurrent HSK.Methods：A multicenter,prospective,randomized,single-blind,and controlled clinical trial was conducted from April 2010 to June 2013.One hundred seventy-three patients （173 eyes involved） who were diagnosed as recurrent HSK definitely,including stromal keratitis and corneal endotheliitis,were divided into three groups randomly：negative control （placebo） group was topically administered with 0.15% GCV ophthalmic gel,4 times per day and 0.1% fluorometholone eye drops,3 times per day until resolution of HSK; positive control acyclovir （ACV） group was topically adopted the same ophthalmic gel and eye drops and additionally received oral ACV 400 mg 5 times a day for 10 weeks and followed by 400 mg 2 times per day for 6 months; test GCV group was topically adopted the same treatment as negative control group and additionally received oral GCV 1000 mg 3 times per day for 8 weeks.The symptoms and signs were evaluated before and after the therapy 1^st week,2^nd week and then followed up every 2 weeks until recovery.Furthermore,we followed up recurrence of HSK for every 3 months after recovery and then assessed the cure time,recurrent rate and adverse reactions.Results：One hundred and seventy-three patients were followed up 7-48 months （mean 32.1 ± 12.3 months）,but 34 patients were failed to follow-up.The cure time was 12.1± 4.3,11.9 ± 4.0 weeks in negative control （placebo） group and positive control ACV group respectively （P =0.991）,which was longer than that in test GCV group （8.6 ± 2.8 weeks） and there was a significant difference between test GCV group and negative control （placebo） group or positive control ACV group （P =0.000）.Furthermore,the recurrent rate was higher in negative control （placebo） group （47.3%） than that in positive control group ACV （26.7%） and test GCV group （17.2%）,and there was a great significant difference among the three groups （P =0.007）,but there was no significant difference between positive control ACV group and test GCV group （P =0.358）.In addition,there was no obvious adverse reaction expect neutropenia （only one patient in test GCV group）.Conclusion：Short-term oral GCV could cure recurrent HSK and endotheliitis,shorten the course,reduce recurrent rate of HSK and have confirmed safety.
基金This work was funded by grants from the National Natural Science Foundation of China （No.81172136 and No.30901821） and the Program for Outstanding Innovative Teams of Higher Learning Institutions of Shanxi.
文摘Background Herpes simplex virus thymidine kinase phosphorylates ganciclovir to ganciclovir monophosphate,which is then converted to ganciclovir triphosphate by endogenous cellular nucleoside kinases.The ganciclovir triphosphate acts as a DNA chain terminator due to the lack of a functional 3＇-OH group and terminates the process of DNA replication,hence leading to cell apoptosis.At present,HSVtk gene usually acts as suicide gene to kill tumor cells.The aim of this study was to investigate the selective cytotoxicity of the herpes simplex virus thymidine kinase/ganciclovir （HSVtK/GCV） suicide gene system controlled by the α-fetoprotein （AFP） promoter on hepatocellular carcinoma （HCC） cells in vitro.Methods pAFP-HSVtk-IRES2-EGFP recombinant plasmid vectors driven by the AFP promoter were constructed.HL-7702 liver cells,HUH-7 HCC,and HepG2 HCC were transfected with the recombinant plasmids.HSVtK gene expression was detected using Western blotting analysis.HepG2 cells line stably expressing HSVtk gene was selected by G418 reagent.The cytotoxicity of HSVtK/GCV suicide gene system on hepatoma cells was measured by CCK-8 reagents when different doses of ganciclovir were added.Results Plasmid pAFP-TK-IRES2-EGFP-expressed HSVtk gene was constructed successfully.HSVtk gene expression level was significantly higher in AFP-positive hepatoma cells than in AFP-negative liver cells.After G418 selection,a HepG2 cells line stably expressing HSVtk gene was acquired.With the increase of the dose of ganciclovir the optical density at 450 nm of HepG2 cells stably expressing HSVtk gene gradually decreased （P ＜0.05）.Conclusion The HSVtK gene-specific expression in hepatoma cells as well as the cytotoxicity of the suicide gene system in HepG2 cells provided the basis for the targeted gene therapy of HCC.
