Adenovirus-mediated Interleukin-24 Research Articles

Effect of adenovirus-mediated interleukin 24 on glioma cells and its mechanism

Objective To investigate the effect of adenovirus-mediated interleukin 24 (Ad-IL-24) on proliferation and apoptosis of glioma cells and its mechanism. Methods We set up Ad-IL-24 group, Ad-GFP group and PBS group. The expression of IL-24 in each group was detected by real-time quantitative PCR (qRT-PCR) and Western blot, and the proliferation activity of 3 groups of U251 cells was detected by MTT assay. Apoptosis of U251 cells was detected by flow cytometry. The expression of Survivin and Bax in U251 cells was detected by qRT-PCR. Results (1) In group PBS and group Ad-GFP, U251 cells adhered well and grew well. The number of adherent growth in group Ad-IL-24 was significantly reduced and the infection efficiency in group Ad-IL-24 and Ad-GFP was above 95%. (2) The results of qRT-PCR and Western blot showed that the expression levels of IL-24 in PBS group and Ad-GFP group were significantly lower than those in Ad-IL-24 group (all P<0.05). (3) U251 cells infected with 100 MOI Ad-IL-24 for 48 h significantly inhibited the growth of U251 cells and the inhibitory effect was significantly higher than that in PBS and Ad-GFP groups (both P<0.05) and presented certain time dependence (P<0.05). (4) The U251 cells were infected with 100 MOI Ad-IL-24 for 48 h. Flow cytometry results showed that the rate of cell apoptosis in Ad-IL-24 group was 39.2%±4.2%, which was significantly higher than that of PBS group and Ad-GFP group (2.5%±1.0% and 4.9%±2.3%, respectively, both P<0.05). (5) The expression level of Survivin in Ad-IL-24 group was significantly lower than that in PBS group and Ad-GFP group (both P<0.05). The expression level of Bax was significantly higher in Ad-IL-24 group than in PBS group and Ad-GFP group (both P<0.05). Conclusions Ad-IL-24 expression could significantly inhibit the growth of U251 cells and induce apoptosis. It is speculated that the mechanism of action may be down-regulating the expression of apoptosis-inhibiting gene Survivin and up-regulating the expression of apoptosis-promoting gene Bax. Key words: Glioma; Cell proliferation; Apoptosis; Interleukin-24; Survivin; Bax

Enhanced in-vitro and in-vivo suppression of A375 melanoma by combined IL-24/OSM adenoviral-mediated gene therapy

Interleukin-24 (IL-24)/melanoma differentiation-associated gene-7 (mda-7) is a unique cytokine-tumor suppressor that displays ubiquitous antitumor properties and tumor-specific killing activity. Oncostatin M (OSM) is the most active IL-6-type cytokine and inhibits the proliferation of various solid tumor cell lines. Multigene-based combination therapy may be an effective practice in cancer gene therapy. The therapeutic potential of a combination of IL-24 and OSM in treating cancers is still elusive. In this study, we aimed to examine the enhanced antitumor activity of adenovirus-mediated IL-24/OSM tumor suppressor gene cotransfer in human melanoma cells. We constructed an IL-24/OSM bicistronic adenovirus and assessed its combined effect on A375 human melanoma cells in vitro and in vivo by detecting and comparing apoptosis in the bicistronic antioncogene group (Ad-IL-24-OSM) and in the IL-24 or OSM single antioncogene group. We also investigated the possible mechanism underlying this effect. The bicistronic adenovirus-mediated coexpression of IL-24 and OSM induced additive growth suppression and apoptosis and an overlapping effect on the upregulation of p21, p53, Bax, and cleaved caspase-3 in vitro and in vivo. Moreover, Ad-IL-24-OSM treatment additively reduced the expression of CDK4 and cyclin D1 in A375 melanoma cells and the expression of CD34 and Cox-2 in A375 xenograft tumors in athymic nude mice. The enhanced antitumor activity elicited by Ad-IL-24-OSM was closely associated with the activation of the apoptotic pathway and the additive inhibition of tumor angiogenesis. Therefore, our results indicate that cancer gene therapy combining two or more tumor suppressors, such as IL-24 and OSM, may constitute a novel and effective therapeutic strategy for treating malignant melanoma and other cancers.

Adenovirus-mediated interleukin-24 enhanced the antitumor effect of radiotherapy on nasopharyngeal carcinoma in vitro and in vivo

To investigate the inhibitory effect of adenovirus-mediated interleukin-24 (AdVIL-24) in conjunction with ionizing radiation on the growth of CNE-2Z human NPC cells in vitro and in vivo and underlying mechanisms. The CNE-2Z cells were transfected with AdVIL-24 alone or combined with radiotherapy. The transfection efficacy of AdVIL-24 in CNE-2Z cells was determined by RT-PCR and Western blot. Cell growth was assessed by MTT assay, apoptosis was detected by flow cytometry through double staining of cells with propidium iodide (PI) and the expressions of P21, P27, cyclin E, CDK2, Bax, Bcl-2 and caspase-3 were detected with semi-quantitative RT-PCR and western blot, respectively. Anti-tumor effect of AdVIL-24 was observed using CNE-2Z human nasopharyngeal carcinoma transplanted tumor in athymic nude mouse model. The volume and weight of the xenografted tumors were measured and the expressions of P21, P27, cyclin E, CDK2, Bax, Bcl-2, caspase-3, CD34 and VEGF and the microvessel density in xenografted tumors were determined by immunohistochemistry analysis. AdVIL-24 plus radiotherapy induced cell growth inhibition (P < 0.05, Q3d, 4d = 0.916, 1.050) , cell cycle G1 phase arrest(50.37%, P < 0.05, Q = 1.042) and apoptosis (48.82%, P < 0.05, Q = 1.042) , substantial up regulations of P21, P27, the ratio of Bax/Bcl-2 and cleaved caspase-3 and down regulations of cyclin E and CDK2 (P < 0.05, QP21 = 0.959, QP27 = 0.956, Qcyclin E = 1.078, QCDK2 = 1.046, QBax/Bcl-2 = 0.995) in vitro. In the xenografted tumors, AdVIL-24 plus radiotherapy induced cell growth inhibition (P < 0.05, Qvolume14 = 1.053, Qweight = 1.004) , apoptosis (P < 0.05, Q = 0.974) , substantial upregulation of P21, P27, the ratio of Bax/Bcl-2 and cleaved caspase-3 and downregulation of cyclin E and CDK2 (P < 0.05; QP21 = 0.920, QP27 = 0.937, QcyclinE = 1.060, QCDK2 = 1.019, QBax/Bcl-2 = 0.982, Qcleaved-Caspase-3 = 0.927) , decreased the tumor vessel CD34 expression and microvessel density. AdVIL-24 potentially blocked the radiation-induced enhancement of VEGF. AdVIL-24 gene therapy combined with radiotherapy may be a novel and effective treatment strategy for human NPC.

Interleukin-24 inhibits cell migration and invasion in the neuroblastoma cell line SH-SY5Y

Neuroblastomas are common pediatric solid tumors with a variable clinical course; approximately 50% of patients present with metastatic disease at diagnosis. The development of metastatic lesions often causes a fatal outcome. Therefore, the prevention of metastases during the early stage of tumor development is critical for the improvement of the prognosis of neuroblastoma patients. We previously observed the suppression of neuroblastoma growth in response to overexpression of interleukin-24 (IL-24) in vitro and in vivo. IL-24 exerts its tumor-suppressive effects by multiple mechanisms, including the balance of Bcl-2 family proteins toward the pro-apoptotic pathway and the activation of the caspase cascade. In this study, we used adenovirus-mediated IL-24 (Ad-IL24) to examine the effect of the ectopic production of IL-24 on cell migration and invasion in human neuroblastoma cells. We found that IL-24 effectively inhibits SH-SY5Y neuroblastoma cell migration and invasion by changing subcellular localization and cellular levels of β-catenin and regulating the levels of proteins associated with cell migration and invasion. Thus, IL-24 should be considered a therapeutic agent that can inhibit primary neuroblastoma growth and that may prevent metastasis.

Adenovirus-mediated IL-24 expression enhances the chemosensitivity of multidrug-resistant gastric cancer cells to cisplatin

Chemotherapy is one of the commonly used strategies in gastric cancer, especially for unresectable patients, but it becomes insensitive to repeated administration of even the most effective chemotherapeutic agents, such as cisplatin. Given this, there is an urgent need for developing chemosensitizers to overcome acquired resistance to chemotherapeutic agents. Interleukin-24 (IL-24), a cytokine-tumor suppressor, shows broad-spectrum and tumor-specific antitumor properties, and studies have demonstrated that IL-24 could conspicuously restore the chemosensitivity of MDR cancer cells. Herein, we developed a human MDR gastric cancer cell subline, SGC7901/CDDP, by repeated selection of resistant clones of parental sensitive cells, and further investigated the chemosensitizing effects and the underlying mechanisms of adenovirus-mediated IL-24 (Ad-IL-24) gene therapy plus CDDP for the human MDR gastric cancer cells SGC7901/CDDP invitro and invivo. The results demonstrated that the expression of IL-24 mRNA and protein was profoundly downregulated in SGC7901/CDDP cells by RT-PCR and western blot analysis. In addition, the cell viability assay showed that the IC50 of SGC7901/CDDP cells to CDDP, 5-FU, ADM and MTX was significantly enhanced compared to parental sensitive SGC7901 cells. Ad-IL-24-induced IL-24 overexpression decreased the IC50 of the above agents (not MTX), induced G2/M cell cycle arrest, and Ad-IL-24 plus CDDP elicited significant apoptosis and tumor suppression of SGC7901/CDDP cells invitro and SGC7901/CDDP cell xenograft tumors invivo, respectively. Moreover, our results demonstrated that the mechanisms of Ad-IL-24-elicited chemosensitizing effects were closely associated with a substantial upregulation of Bax and downregulation of P-gp and Bcl-2 in SGC7901/CDDP cells invitro and SGC7901/CDDP xenograft tissues invivo. Thus, this study indicates that overexpression of IL-24 gene can significantly promote chemosensitivity in MDR phenotype SGC7901/CDDP gastric cancer cells.

Enhanced therapeutic efficacy of adenovirus-mediated interleukin-24 gene therapy combined with ionizing radiotherapy for nasopharyngeal carcinoma

Melanoma differentiation-associated gene-7 (mda-7)/interleukin-24 (IL-24), a unique cytokine tumor suppressor, displays ubiquitous antitumor activities and cancer-specific cytotoxicities via multiple signaling pathways. In the present study, we investigated the antitumor effect of adenovirus-mediated IL-24 (AdVIL-24) gene therapy in conjunction with ionizing radiation on CNE-2Z human nasopharyngeal carcinoma (NPC) cells in vitro and in vivo in athymic nude mice, and its potential mechanisms. We demonstrated that AdVIL-24 gene therapy plus ionizing radiotherapy induced enhanced growth inhibition, cell cycle G1 phase arrest and apoptosis in vitro in CNE-2Z human NPC cells and in vivo in CNE-2Z xenografted tumors subcutaneously implanted in athymic nude mice. Mechanistically, AdVIL-24 combined with ionizing radiation led to the substantial upregulation of P21 and P27 cyclin-dependent kinase (CDK) inhibitors, ratio of pro-apoptotic to anti-apoptotic molecules Bax/Bcl-2 and cleaved caspase‑3 as well as downregulation of cyclin E and CDK2 in vitro and in vivo in CNE-2Z human NPC cells. Furthermore, AdVIL-24 plus radiation additively reduced the tumor vessel CD34 expression and microvessel density in vivo. More importantly, AdVIL-24 potentially blocked the radiation-induced enhancement of vascular endothelial growth factor (VEGF), a pro-angiogenic factor. The enhanced antitumor activity against NPC elicited by AdVIL-24 gene therapy combined with ionizing radiotherapy was closely associated with the enhanced induction of G1 phase arrest and apoptosis via additive modulation of cell cycle regulatory molecules and activation of intrinsic apoptotic pathways, and the overlapping inhibition of tumor angiogenesis. Thus, our results suggest that AdVIL-24 gene therapy combined with ionizing radiotherapy may be a novel and effective treatment strategy for human NPC.

Double-Regulated Oncolytic Adenovirus-Mediated Interleukin-24 Overexpression Exhibits Potent Antitumor Activity on Gastric Adenocarcinoma

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24), identified by subtraction hybridization in the mid-1990s, is a potent gene therapeutic for cancer. Using a replication-deficient adenovirus as vector, it provokes apoptosis in diverse cancer cells without harming normal cells or tissues. To exploit the anticancer capability of IL-24 to the best, in this study, we generated a novel gene-virotherapy agent MUD55-IL-24, utilizing a replication-competent oncolytic adenovirus MUD55 as the gene delivery vector. It was documented that MUD55-IL-24 exhibited much stronger antitumor activity on gastric carcinoma both in vitro and in vivo, and its safety was comparable to the replication-deficient adenovirus Ad-IL-24. The unique properties of IL-24, including apoptosis induction, antiangiogenesis, and antimigration, were all significantly enhanced in MUD55-IL-24. After looking into the underlying mechanism, we found that intracellular ROS (Reactive Oxygen Species) generation may have caused the induction of apoptosis, mitochondrial dysfunction, and the activation of caspases in MUD55-IL-24-infected SG-7901 cells. Taken together, these results suggest that MUD55-IL-24 may be able to provide a potential strategy for future treatment of human gastric carcinoma.

TheIn VitroandIn VivoAntitumor Activity of Adenovirus-Mediated Interleukin-24 Expression for Laryngocarcinoma

Interleukin-24 (IL-24)/melanoma differentiation associated gene-7 (mda-7) as a novel tumor-suppressor gene has potent antitumor activities in a broad spectrum of human cancers through the activation of various signaling pathways. However, the suppressive effect of adenovirus-mediated IL-24 (Ad-IL-24) expression on human laryngeal cancers is still elusive. In this study, we explored the therapeutic effect of Ad-IL-24 on human laryngeal cancers in vitro and in vivo in an athymic nude mouse model, using a Hep-2 human laryngocarcinoma cell line, and a WI-38 human diploid cell line served as a normal cell control. We demonstrated that Ad-IL-24 induced significant growth inhibition and apoptosis, upregulated the expression of P21, P27, and Bax, downregulated Bcl-2 expression, and activated caspase-3 in Hep-2 laryngeal tumor cells, while it exerted no direct effect on the in vitro proliferation of WI-38 normal diploid cells. Moreover, intratumoral injections of Ad-IL-24 in nude mice bearing Hep-2 tumors significantly suppressed the laryngeal xengrafted tumor growth and reduced microvessel density (MVD) and VEGF expression in tumors. This retarded tumor growth in vitro and in vivo elicited by Ad-IL-24 was closely associated with the upregulation of proliferation-related molecules P21 and P27, decrease in the ratio of anti- to proapoptotic molecules Bcl-2/Bax, followed by the activation of caspase-3, leading to apoptosis via intrinsic apoptotic pathways, and the reduced expression of proangiogenic factor VEGF involved in the inhibition of tumor angiogenesis. Thus, our results indicate that the potent, selective killing activity of Ad-IL-24 in laryngeal cancer cells, but not in normal cells, makes this vector a potential candidate for laryngeal cancer gene therapy.