Correction: Reasons for COVID-19 Vaccine Hesitancy Among Chinese People Living With HIV/AIDS: Structural Equation Modeling Analysis.

[This corrects the article DOI: 10.2196/33995.].

Reasons for COVID-19 Vaccine Hesitancy Among Chinese People Living With HIV/AIDS: Structural Equation Modeling Analysis.

BACKGROUND: Many countries and organizations recommended people living with HIV/AIDS (PLWHA) receive the COVID-19 vaccine. However, vaccine hesitancy still exists and becomes a barrier for promoting COVID-19 vaccination among PLWHA. OBJECTIVE: This study aims to investigate factors that contributed to COVID-19 vaccine hesitancy among PLWHA. METHODS: The study used a multicenter cross-sectional design and an online survey mode. We recruited PLWHA aged 18-65 years from 5 metropolitan cities in China between January 2021 and February 2021. Participants completed an online survey through Golden Data, a widely used encrypted web-based survey platform. Multiple linear regression models were used to assess the background characteristics in relation to COVID-19 vaccine hesitancy, and structural equation modeling was performed to assess the relationships among perceived benefits, perceived risks, self-efficacy, subjective norms, and COVID-19 vaccine hesitancy. RESULTS: Among 1735 participants, 41.61% (722/1735) reported COVID-19 vaccine hesitancy. Older age, no other vaccinations in the past 3 years, and having chronic disease history were positively associated with COVID-19 vaccine hesitancy. Structural equation modeling revealed a direct relationship of perceived benefits, perceived risks, and subjective norms with self-efficacy and vaccine hesitancy and an indirect relationship of perceived benefits, perceived risks, and subjective norms with vaccine hesitancy. Moreover, self-efficacy toward COVID-19 vaccination was low. PLWHA had concerns of HIV disclosure during COVID-19 vaccination. Family member support could have an impact on COVID-19 vaccination decision-making. CONCLUSIONS: COVID-19 vaccine hesitancy was high among PLWHA in China. To reduce COVID-19 vaccine hesitancy, programs and strategies should be adopted to eliminate the concerns for COVID-19 vaccination, disseminate accurate information on the safety and efficacy of the COVID-19 vaccine, encourage family member support for COVID-19 vaccination, and improve PLWHA's trust of medical professionals.

Changes in NK Cell Subsets and Receptor Expressions in HIV-1 Infected Chronic Patients and HIV Controllers.

Natural killer (NK) cells are major effectors of the innate immune response and purported to play an influential role in the spontaneous control of HIV infection. In the present study, we compared the phenotypes of NK cells in the peripheral blood of three groups of subjects with chronic HIV-1 infection, HIV controllers, and healthy donors. The results showed that CD56+/CD16- NK cell subsets decreased in chronic patients and remained unchanged in controllers. Notably, we found that people living with chronic HIV-1 infection had suppressed NKp80, NKp46, and NKG2D expressions on NK cells compared to healthy donors, while HIV controllers remained unchanged. In contrast, NKG2D expression was substantially higher in controllers than in chronic patients (M=97.67, p<0.001). There were no significant differences in inhibitory receptors KIR3DL1 and KIR2DL1 expressions. In addition, plasma cytokine IFN-γ, TNF-α and IL-12showed higher levels in HIV controllers compared to chronic patients. Overall, our study revealed that, as compared to chronic patients, HIV controllers show an increased activating receptors expression and higher number ofCD56+/CD16-NK cell subset, with increased expression levels of plasma cytokines, suggesting that higher immune activation in controllers may have a key role in killing and suppressing HIV.

The current status of syphilis prevention and control in Jiangsu province, China: A cross-sectional study.

OBJECTIVE: To analyze the midterm evaluation data from the National Syphilis Prevention and Control Plan (2010-2020) and evaluate the current status of syphilis prevention and control in Jiangsu province, China. METHODS: We collected data via (1) field surveys conducted in 2015 and (2) data recorded in existing syphilis surveillance systems. We conducted descriptive statistical analysis to evaluate the current landscape of syphilis control initiatives and their potential effect in syphilis control. RESULTS: The incidence of all cases of syphilis decreased from 2010 (32.3 per 100,000) to 2015 (30.1 per 100,000), with an annual growth of -1.17% (x2trend = -7.52, P<0.001) in Jiangsu province. The incidence of primary and secondary syphilis and congenital syphilis both decreased significantly from 2010 to 2015. The average awareness rate of syphilis knowledge among professional personnel was 95.4% (3781/3963). Rural residents had the lowest awareness rate (83.5%, 1875/2245) and commercial sex workers had the highest awareness rate (92.1%, 7804/8474) in 2015. Only 47.8% (33908/70894) of patients received provider-initiated syphilis counseling and testing (PISTC) services in sexually transmitted disease (STD) clinics, but 94.5% (87927/93020) of all syphilis patients received free testing for syphilis. Overall, 97.2% (9378/9648) of syphilis reported cases of syphilis at medical institutions were confirmed to be accurate, and 92.2% (5850/6345) of patients diagnosed with syphilis at medical institutions received treatment with penicillin. CONCLUSION: The syphilis incidence rate in Jiangsu has decreased in recent years, but remains at a high level. It is essential to promote PISTC services to improve knowledge of syphilis and rates of testing and treatment in Jiangsu province.

High HIV incidence epidemic among men who have sex with men in china: results from a multi-site cross-sectional study.

BACKGROUND: Recent upsurge of new HIV infections among men who have sex with men (MSM) is a major concern in China. Paucity of national-level information regarding the burden and predictors of this progressive epidemic of new infections called for a multi-centric, timely and comprehensive investigation. METHODS: Mixed methods were used to recruit MSM from seven cities in China between 2012 and 2013. Recent and established HIV infections were estimated by Western Blot and BED HIV-1 capture enzyme immunoassay. Syphilis and herpes simplex virus-2 (HSV-2) were also tested. RESULTS: A total of 4496 eligible MSM were recruited. The majority was aged ≤35 years (77.5 %), migrants (60.3 %), never married (69.8 %), and played receptive role in anal sex (70.5 %). The HIV prevalence was 9.9 %, and 41.9 % were recently infected, with sensitivity/specificity adjusted HIV incidence of 8.9 (95 % CI: 7.6-10.2)/100 Person-Years. The prevalence of history HSV-2 and syphilis were 12.5 % and 8.5 %, respectively. Recent HIV infection was associated with having multiple male partners (aOR = 1.4, 95 % CI 1.1-1.9), recreational drug use (aOR = 2.2, 95 % CI 1.6-3.0), anal bleeding (aOR = 2.1, 95 % CI 1.4-3.0), syphilis infection (aOR = 2.8, 95 % CI 1.9-4.3) and history HSV-2 infection (aOR = 2.3, 95 % CI 1.5-3.3). CONCLUSION: High rate of recent HIV infection is potentially resulting in progressive deterioration of the overall HIV epidemic among MSM in China. Targeted interventions to address high-risk MSM including those having multiple partners, history of recreational drug use and syphilis or HSV-2 infection seemed to be the need of the hour.

The epidemic of HIV, syphilis, chlamydia and gonorrhea and the correlates of sexual transmitted infections among men who have sex with men in Jiangsu, China, 2009.

BACKGROUND: In China, the HIV/AIDS epidemic is expanding among men who have sex with men (MSM). As independent risk factors of HIV infection, the epidemics of Chlamydia (CT) and Gonorrhea (NG) in MSM were not well studied, particular for the risk factors of these infectious. The objectives of current reported study were to understand the dynamics of HIV and other sexual transmitted infections (STIs) among MSM in Jiangsu, China, and to measure factors that correlated with STIs. METHODS: In order to gain more participants, a multisite cross-sectional study design was used in our study, by using convenience-sampling to recruit MSM in two Changzhou and Yangzhou, Jiangsu, China, between the July and October of 2009. RESULTS: In this comprehensive survey involving MSM in two cities of Jiangsu province of China, the prevalence of STIs of CT (6.54%), NG (3.63%), syphilis (20.34%) and HIV (11.62%) were measured. Overall, the STIs prevalence (CT, NG or syphilis) for the participants in our study was 26.39%, meanwhile, 3.4% (14 out of the 413) participants had at least two kinds of STIs. Meeting casual partners at parks, public restrooms or other public areas, having had anal sex with men in the past six months, having had STI symptoms in the past year were positively correlated with STIs positive, with adjusted ORs of 4.61(95%CI 1.03-20.75), 1.91(95%CI 1.14-3.21) and 2.36(95%CI 1.07,5.24). CONCLUSION: Our study findings reiterate the fact that Chinese MSM are highly susceptible to acquiring syphilis, CT, NG and HIV, and there is an urgent need for intervention targeted towards this population. Behavioral measures should constitute an important part of the targeted intervention. Furthermore, the already implemented preventive and diagnostic services for HIV should be expanded to include syphilis CT and NG, too.

siRNA against KIR3DL1 as a potential gene therapeutic agent in controlling HIV-1 infection.

OBJECTIVES: The aim of this study was to develop a small interfering RNA (siRNA) against the expression of KIR3DL1 receptor on natural killer (NK) cells, in order to promote the ability of NK cells to destroy human immunodeficiency virus (HIV)-infected cells and thus prevent failure of siRNA therapy targeting human immunodeficiency virus type 1 (HIV-1) virus among HIV-1 infected patients in vitro. METHODS: A siRNA targeting KIR3DL1 was synthesized and then modified with cholesterol, methylene, and sulfate. The inhibitory action of the siRNAs on primary cultured NK cells was detected. The amount of IFN-γ and TNF-α secretions in NK cells was measured. The intended functions of NK cells in vitro were analyzed by CFSE and PI methods. RESULTS: There were no significant differences in inhibiting the expression of KIR3DL1 on NK cells between the modified and unmodified siRNAs, while inhibition by each of them differed significantly from controls. The amount of IFN-γ and TNF-α secretions in the NK cells was abundant due to unsuccessful expression of KIR3DL1 on NK cells, which further promoted function of the NK cells. CONCLUSION: The siRNA against KIR3DL1 could enhance the ability of the NK cells to kill the HIV-1 infected cells in vitro and successfully prevented the failure of siRNA therapy targeting the HIV-1 virus. Therefore, it can act as a potential gene therapeutic agent among HIV-1 infected people.

Syphilis and its correlates among heterosexual males attending sexually transmitted infection clinics - observation from a multicity cohort in Jiangsu Province, China.

OBJECTIVES: To estimate the prevalence of HIV and syphilis, incidence of syphilis and to identify the correlates of syphilis infection among heterosexual male attendees of sexually transmitted infection (STI) clinics (MSC). METHODS: A cohort study of one-year duration was conducted in Yangzhou and Changzhou cities in Jiangsu province of China. The baseline survey commenced in June 2009, recruited 1225 consenting adult MSCs (609 in Yangzhou and 617 in Changzhou) through STI-clinic based convenience sampling. RESULTS: Baseline HIV and syphilis prevalence were 0.49% and 17.29% respectively. Syphilis incidence rate was 7.22 per 100 person-years (6.53 in Yangzhou and 7.76 in Changzhou) during the 6-month follow-up with retention fractions of 27.38% and 35.15% for Yangzhou and Changzhou respectively. Majority of the participants were middle-aged, high school educated, married, living with partners and non-migrants. Very few subjects reported recent and consistent condom-use with regular partners. Although considerable number of MSCs reported recent sexual exposure with female sex workers (FSW) and non-FSW casual partners, the proportion of reported condom use was very low during those exposures. In multivariate analyses higher age, having recent sex with FSWs and being HIV-positive were associated with higher syphilis sero-positivity while higher education was protective. In bivariate analyses, being married, divorced/widowed, official residency of the study cities and non-use of condom with regular partners predicted higher risk. CONCLUSIONS: Considering the potential bridging role of MSCs between high and low-risk populations, effective intervention strategies among them targeting the correlates of syphilis infection are urgently called for in Jiangsu province of China.

Worsening epidemic of HIV and syphilis among men who have sex with men in Jiangsu Province, China.

BACKGROUND: Epidemics of human immunodeficiency virus (HIV) and syphilis among men who have sex with men (MSM) are major public health concerns in most parts of China. A dearth of information regarding the current trend of HIV in this hard-to-reach population in several regions including Jiangsu, coupled with the reemergence of syphilis, calls for an effort to understand the dynamics of the dual epidemic in this province. METHODS: To estimate the occurrence and burden of these 2 sexually transmitted diseases and the distribution of their potential sociobehavioral correlates among MSM in Jiangsu, 2 cohort studies were conducted in Yangzhou and Changzhou cities. RESULTS: Among 839 participants, 48% were married, 51.7% had sex with women in the last 6 months, and 25.5% did not use condoms during their last anal intercourse. The observed incidence of HIV was 13.59 and 12.62 and that of syphilis was 7.33 and 13.25 per 100 person-years among the participants of Yangzhou and Changzhou, respectively. The baseline prevalence of HIV and syphilis was 16.0% and 29.9% in Yangzhou and 13.6% and 14.9% in Changzhou, respectively. CONCLUSIONS: Considerably high incidence and prevalence of HIV and syphilis among participants and their potential bridging role in transmitting these infections to the general population in Yangzhou and Changzhou cities calls for urgent effective intervention strategies.

Correlates of chlamydia and gonorrhea infection among female sex workers: the untold story of Jiangsu, China.

OBJECTIVES: To estimate the prevalence of sexually transmitted infections (STIs) among female sex workers (FSWs) in the Jiangsu Province, China and measure the association of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections with their potential correlates. DESIGN: A cross-sectional study on a representative sample of FSWs in Yangzhou and Changzhou cities of Jiangsu was conducted. METHODS: 185 sex-work venues in Yangzhou and 174 in Changzhou were selected by stratified random sampling. 2972 FSWs (1108 in Yangzhou and 1864 in Changzhou), aged 15 years or more, who agreed to participate and provided blood sample for HIV and syphilis testing were interviewed in these venues. Cervical specimens from 849 randomly chosen participants were then tested for CT and NG. RESULTS: Proportions of young, school-educated, currently married FSWs who were living alone, migrated from other provinces and engaged in unprotected vaginal intercourse in past 3 months (UVI) were relatively high. Prevalence of HIV, syphilis, CT and NG were 0.20%, 4.88%, 14.61% and 5.42% respectively. Younger age, living alone or with persons other than partners/family members, engaging in UVI and having other STIs seemed to be associated with higher risk of CT or NG infection. Being divorced/widowed and working in middle/low-level venues were identified as additional risk factors for NG. CONCLUSIONS: Based on a representative sample, this initial effort to identify the correlates of CT/NG infections among FSWs of Jiangsu revealed that focused interventions targeting high-risk FSWs are urgently required for controlling STI epidemics in Yangzhou and Changzhou where substantial number of STI cases were identified.

The prevalences of Neisseria gonorrhoeae and Chlamydia trachomatis infections among female sex workers in China.

BACKGROUND: Sexually transmitted infections (STIs) have become a major public health problem among female sex workers (FSWs) in China. There have been many studies on prevalences of HIV and syphilis but the data about Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) infections are limited in this population in China. METHODS: A cross-sectional study was performed among FSWs recruited from different types of venues in 8 cities in China. An interview with questionnaire was conducted, followed by collection of a blood and cervical swab specimens for tests of HIV, syphilis, NG and CT infections. RESULTS: A total of 3,099 FSWs were included in the study. The overall prevalence rates of HIV, syphilis, NG and CT were 0.26%, 6.45%, 5.91% and 17.30%, respectively. Being a FSW from low-tier venue (adjusted odds ratios [AOR]=1.39) had higher risk and being age of ≥ 21 years (AOR=0.60 for 21-25 years; AOR=0.29 for 26-30 years; AOR=0.35 for 31 years or above) had lower risk for CT infection; and having CT infection was significantly associated with NG infection. CONCLUSIONS: The high STI prevalence rates found among FSWs, especially among FSWs in low-tier sex work venues, suggest that the comprehensive prevention and control programs including not only behavioral interventions but also screening and medical care are needed to meet the needs of this population.

Asymmetric siRNA targeting the bcl­2 gene inhibits the proliferation of cancer cells in vitro and in vivo.

Small interfering RNAs (siRNAs) are valuable reagents for efficient gene silencing in a sequence­specific manner via the RNA interference (RNAi) pathway. The current synthetic siRNA structure consists of symmetrical duplexes of 19­21 base pairs (bp) with 2 nucleotide (nt) 3' overhangs. In this study, we report that an asymmetric siRNA (asiRNA) consisting of 17 bp duplex region (17 bp asiRNA) exhibited potent activity in inhibiting bcl-2 gene expression and cancer cell proliferation in vitro. Importantly, this asiRNA structure significantly reduced off­target silencing by the sense strand. To improve the stability of the 17 bp asiRNA, we synthesized a series of chemically modified 17 bp asiRNAs. Further experiments showed that in comparison with the 17 bp asiRNA, the 17 bp asiRNA­M2, one of the modified 17 bp asiRNAs, exhibited a comparable gene silencing activity and an improved stability in vitro. Furthermore, the 17 bp asiRNA­M2 with a proteolipid micelle delivery system can effectively suppress the growth of H22 and BGC 803 tumors in vivo. These results suggest that the chemically modified asiRNAs may have potential as an effective therapeutic approach for cancer gene therapy in the future.

Emergence of peripheral CD3+CD56+ cytokine-induced killer cell in HIV-1-infected Chinese children.

Cytokine-induced killer (CIK) cells are immune effector cells characterized by co-expression of CD3 and CD56 molecules. We examined the quantities of CIK cells and the changes of these cell expressing NK cell receptors in HIV-1-positive children infected via mother-to-child transmission. The percentage of CIK cells was quantified and the changes in the surface cell receptor profiles in 18 HIV-1-infected children were examined. We found that CIK cell percentages were dramatically increased in HIV-1-infected children. Furthermore, the expressions of CD16, NKp30, NKp44, NKp46, NKp80 and CD244 on CIK cells were decreased, while the expressions of KIR3DL1 and NKG2D on CIK cells were increased in HIV-1-infected children. However, the expressions of KIR2D and NTB-A on CIK cells did not change in the HIV-1-infected children. CIK cells possessed the characteristics of promoting the maturation of dendritic cells and killing functions in HIV-1-infected children. Moreover, serum concentrations of IL-4 and IFN-γ were significantly increased in HIV-1-infected children compared with the HIV-negative controls. These changes likely occurred as a protective mechanism against transmission of maternal HIV-1 virus and thereby helped to limit viral spread, eliminate infected cells and help HIV-1-infected patients to slow the progression to AIDS.

Chinese human immunodeficiency virus-1 patients with different routes of transmission exhibit altered expression levels of blood dendritic cell subpopulations.

Dendritic cells (DCs) play a pivotal role in the pathogenesis of human immunodeficiency virus-1 (HIV-1). Reduced numbers of blood DCs have been observed in individuals with chronic HIV-1 infection. In the present study, we analyzed the expression levels of monocytes, myeloid dendritic cell (mDC) precursors, mDCs, and plasmacytoid dendritic cells (pDCs), in HIV-1-infected patients in China who were infected via different routes of transmission, including heterosexual and homosexual sexual contact, and blood transmission through importation of blood or blood products, to further elucidate their role in HIV. Compared with HIV-negative individuals (n = 40), relative levels of CD11c+CD14⁻mDCs, CD11c++CD123(low) mDCs, and CD11c⁻CD123+ pDCs in total peripheral blood mononuclear cells (PBMCs) were significantly lower in all HIV patients (n = 93), and in those with blood transmission (n = 26) and heterosexual transmission (n = 43), while relative levels of CD11c+CD14⁻mDCs were significantly lower in HIV patients infected via homosexual transmission (n = 24). The results of correlation analysis demonstrated a significant negative correlation between CD4+ T-cell counts and the relative levels of CD11c++CD123(low) mDCs in HIV-I patients infected via blood transmission. There was no significant correlation between CD4+ T-cell counts and the expression level of other DC subpopulations in PBMCs from HIV patients. The results of this study suggest that HIV-1 patients with different routes of transmission exhibit altered expression levels of blood DC subpopulations, which contributes to dysregulated immune responses and pathogenesis of HIV-1.

[Analysis on sexually transmitted diseases and the related risk factors among men who have sex with men in Jiangsu province].

OBJECTIVE: To investigate infections of syphilis, neisseria gonorrhoeae, chlamydia trachomatis and the related risk factors in men who have sex with men (MSM) in Jiangsu province. METHODS: A total of 400 MSM were enrolled by Snowball Sampling Method from August to October in 2010 and then 328 cases were surveyed by a questionnaire and collected serum sample 5 ml per person as well as rectal swab on the spot; all of the serum samples were tested for syphilis by ELISA and TRUST, and all of the rectal swabs were tested for neisseria gonorrhoeae or chlamydia trachomatis. The influencing factors of syphilis, neisseria gonorrhoeae, chlamydia trachomatis were analyzed by logistic regression analysis. RESULTS: The 328 MSM were (32.46 ± 9.72) years old, 59.15% (194/328) were unmarried.75.00% (246/328) MSM had rectal sex with men in the past 3 months, and condom use rate for recent sex was 56.71% (186/328), while 53.05% (174/328) MSM didn't have sex with women in the last 3 months. The syphilis infection rate among MSM was 13.41% (44/328), the neisseria gonorrhoeae infection rate was 3.66% (12/328), and the chlamydia trachomatis rate was 11.59% (38/328). The number of sex partners was the key factor that influenced syphilis infections (OR = 4.213, 95%CI: 1.133 - 15.656). CONCLUSION: The prevalence of syphilis and chlamydia trachomatis was high in MSM in Jiangsu, while risk behavior rate were high in the MSM and then should be intervened.

Differences in natural killer cell quantification and receptor profile expression in HIV-1 infected Chinese children.

Natural killer (NK) cells are believed to play a role in the progression of human immunodeficiency virus 1 (HIV-1) disease, and NK cell levels are reduced in individuals with chronic HIV-1 infection. To assess the effects on quantity of NK cells and the changes of NK cell receptors in HIV-1 infected children via mother-to-child transmission, the percentage of NK cells is quantified and the changes in the NK cell receptor profiles in 20 HIV-1 infected children who are not progressing into AIDS were examined. The results showed that NK cell percentage was decreased in the HIV-1 infected children. The expression of NKp30 on NK cells was increased, while the expressions of CD16, NKp44, NKp46, NKp80, NTB-A, CD244, KIR2D, KIR3DL1 and NKG2D on NK cells were decreased in the HIV-1 infected children. NK cell cytolytic activity was elevated in HIV-1 infected children. These results indicate that the acute changes in NK cell percentage and NK cell receptors in HIV-1 infected children are different from the HIV-1 infected adult individuals. Moreover, serum concentrations of IL-18 were elevated in HIV-infected children compared to HIV-uninfected controls. These differences probably play a role in protecting against transmission of maternal HIV-1 virus and guiding the therapeutic strategies for HIV-1 infected children.

Changes in NK cell counts and receptor expressions and emergence of CD3(dim)/CD56+ cells in HIV-1 infected patients in China.

Natural killer (NK) cells are believed to play a role in human immunodeficiency virus 1 (HIV-1) disease progression, and NK cell levels are reduced in individuals with chronic HIV-1 infection. In the present study, we compared the frequency and phenotype of peripheral blood CD3-CD56+ NK cells in HIV-1 infected patients in China who were infected through different routes of transmission, including heterosexual and homosexual sexual contact, and blood transmission through injection drug use or importation of blood or blood products. The results showed significantly reduced numbers of CD3-CD56+ NK cells with no association with route of transmission. The expression of CD16 on CD3-CD56+ NK cells in HIV-1 infected patients was similar to that in healthy controls. Among the examined receptor (KIR3DL1, NKp80, NKp44, CD244, NKG2D, and NTBA) expressions, only KIR3DL1 and NKp80 expressions on CD3-CD56+ NK cells were suppressed in HIV-1-infected patients compared to healthy controls, and no significant difference was observed between patients upon comparison of different routes of transmission. A subset of CD3(dim)/CD56+ cells was dramatically increased in HIV-1-infected patients. This study suggests that changes in NK cell count and receptors are not related to the route of HIV-1 transmission. A new subset of CD3(dim)/CD56+ cells emerged only in HIV-1-infected patients, and may play a role in limiting viral spread, eliminating infected cells, and slowing the progression from HIV-1 infection to AIDS.

Liposomal plasmid DNA encoding human thymosin alpha and interferon omega potently inhibits liver tumor growth in ICR mice.

AIM: To evaluate the potential therapeutic effect of liposomal gene delivery, genes encoding for human thymosin alpha1 (Talpha1) and interferon omega1 were injected via the tail vein into mice bearing a Hep-A-22 liver tumor. METHODS: The cDNA of human Talpha1 and interferon omega1 were obtained by synthesis or reverse transcription-polymerase chain reaction (RT-PCR), respectively. Eukaryotic expressing vectors pIRES2, encoding Talpha1 and/or interferon omega1, were constructed and injected with liposome via the tail vein into ICR mice bearing a Hep-A-22 tumor. The potency of tumor inhibition was evaluated when three treated groups were compared with the group receiving the empty vector. Apoptosis of tumor cells was investigated by analyzing DNA fragmentation. RESULTS: Only the group treated with dual-gene plasmid reached an eligible level of tumor inhibition (43%). The difference in tumor weight was statistically significant between the Talpha1 gene or the interferon omega1 gene treated groups and the control (P<0.05), and highly significant between the dual-gene treated group and the control (P<0.01). DNA ladder was observed in the tumor cells from the purpose gene treated groups but not from the control. CONCLUSION: The dual-gene plasmid-liposome complex showed more potent inhibition than the single gene constructs on the growth of Hep-A-22 tumor cells in mice, which may be attributed to indirect and additive induction of apoptosis in tumor cells by increased expression of Talpha1 and interferon omega1.

RNA interference remarkably suppresses bcl-2 gene expression in cancer cells in vitro and in vivo.

Bcl-2 is an anti-apoptotic protein. If the level of Bcl-2 protein can be reduced sufficiently in tumors using RNA interference (RNAi) to target the gene message, the apoptosis of tumor cells may be promoted. In this study, we synthesized 19 nucleotides (nts) small interference RNA (siRNA) constructs suppressing bcl-2 gene expression in human tumor cells (HeLaB2 and BGC-823 cell lines) in vitro. The bcl-2 gene expression levels were significantly reduced when these siRNA were transfected into experimental two tumor cells for 72 hours. The apoptosis process was also examined in the tumor cells. Here we synthesized siRNA from a DNA template under the control of the RNA polymerase III promoter in transfected tumor cells. Using this DNA vector-based approach, we found that the siRNA efficiently and specifically inhibited the synthesis of protein encoded by the bcl-2 gene in HeLaB2 and BGC-823 tumor cells. Tumor growth was inhibited by 66.5% with 2mg/kg pSilencer 3.1H1-bcl-2 in mouse liver tumor-bearing BALB/c mice. This approach may prove to be a valuable clinical technique for the analysis of specific gene functions and gene therapy of malignant tumors that utilize the bcl-2 gene via RNA interference.