Antitumor activity of an adenovirus harboring human IL-24 in colon cancer

The use of adenoviral vectors in gene therapy and vaccine approaches

Adenovirus was first identified in the 1950s and since then this pathogenic group of viruses has been explored and transformed into a genetic transfer vehicle. Modification or deletion of few genes are necessary to transform it into a conditionally or non-replicative vector, creating a versatile tool capable of transducing different tissues and inducing high levels of transgene expression. In the early years of vector development, the application in monogenic diseases faced several hurdles, including short-term gene expression and even a fatality. On the other hand, an adenoviral delivery strategy for treatment of cancer was the first approved gene therapy product. There is an increasing interest in expressing transgenes with therapeutic potential targeting the cancer hallmarks, inhibiting metastasis, inducing cancer cell death or modulating the immune system to attack the tumor cells. Replicative adenovirus as vaccines may be even older and date to a few years of its discovery, application of non-replicative adenovirus for vaccination against different microorganisms has been investigated, but only recently, it demonstrated its full potential being one of the leading vaccination tools for COVID-19. This is not a new vector nor a new technology, but the result of decades of careful and intense work in this field.

Luteolin enhances the antitumor efficacy of oncolytic vaccinia virus that harbors IL-24 gene in liver cancer cells

BACKGROUND

Interleukin 24 (IL-24) is an IL-10 family member and a secreted cytokine characterized by cancer-targeted toxicity and can activate apoptosis by sensitizing cancer cells to chemotherapy. Cytotoxic effects of luteolin on different types of cancer cells suppress their growth by acting on the components of the apoptosis signaling cascade. Therefore, our study aimed to prove whether oncolytic vaccinia virus (VV) that harbors IL-24 (VV-IL-24) combine with luteolin exerts a synergistic inhibitory effect in liver cancer cells.

METHODS

Impacts on cell viability of VV-IL-24 and luteolin were assessed by MTT in various liver cancer cell lines. Then, liver cancer cell apoptosis was analyzed via flow cytometry and Western blotting. Besides, the MHCC97-H xenograft mouse model was employed as a means of assessing in vivo antitumor efficacy.

RESULTS

MTT assay confirmed that the combination treatment decreased liver cancer cells viability to a greater degree than treatment with VV-IL-24 or luteolin alone. Flow cytometry and Western blot assay proved that VV-IL-24 plus luteolin induced more liver cancer cells apoptosis than single treatment. Furthermore, in the MHCC97-H xenograft model, 15 days of treatment with VV-IL-24 plus luteolin inhibited tumor growth significantly more than single treatment.

CONCLUSION

These data confirm that the synergistic mechanism of VV-IL-24 and luteolin elicits a stronger tumor growth inhibition than any single therapy. Thus, the combination of VV-IL-24 and luteolin could provide the basis for preclinical research in the treatment of liver cancer.

Interleukin-24 Regulates T Cell Activity in Patients With Colorectal Adenocarcinoma

Interleukin (IL)-24 plays a potential anti-tumor activity in colorectal cancer in a dose-dependent manner. However, the immunoregulatory role of IL-24 to peripheral and tumor-infiltrating T cell function in colorectal cancer was not fully elucidated. In this study, twenty-nine colorectal adenocarcinoma patients and fifteen healthy individuals were enrolled. IL-24 expression and IL-24 receptor (IL-20R1, IL-20R2, and IL-22R1) mRNA relative level was measured by ELISA and real-time PCR, respectively. CD4⁺ and CD8⁺ T cells were purified from peripheral bloods and cancer specimens, and were stimulated with low (10 ng/ml) and high (100 ng/ml) concentration of recombinant IL-24. CD4⁺ T cells activity was assessed by measurement of Th cell percentage, transcriptional factors, and cytokine production. CD8⁺ T cells activity was evaluated by investigation of cytotoxic molecules, target cell death, and interferon-γ (IFN-γ) secretion. IL-24 was decreasingly expressed in both peripheral bloods and cancer tissues in colorectal adenocarcinoma patients. However, IL-20R1 and IL-20R2 was comparable between healthy controls and colorectal adenocarcinoma patients. Low concentration of IL-24 suppressed CD4⁺ T cell proliferation. In contrast, high concentration of IL-24 not only promoted CD4⁺ T cell proliferation, but also enhanced CD4⁺ T cell activity, which mainly presented as up-regulation of Th1/Th17 frequency, T-bet/RORγt mRNA, and IFN-γ/IL-17 production but down-regulation of Treg percentage, FoxP3 mRNA, and IL-10/IL-35 secretion. Moreover, high concentration of IL-24 also increased perforin and granzyme B expression in CD8⁺ T cells, and elevated cytolytic and non-cytolytic activity of CD8⁺ T cells, which presented as induction of target cell death and elevation of IFN-γ expression. However, low concentration of IL-24 did not affect bioactivity of CD8⁺ T cells. The current data indicated that IL-24 might regulate T cell function in a dose-dependent manner. High-concentration of IL-24 might promote anti-tumor immune responses in development novel therapeutic approaches to colorectal adenocarcinoma.

Oncolytic Adenovirus Harboring Interleukin-24 Improves Chemotherapy for Advanced Prostate Cancer

PURPOSE

Oncolytic adenoviruses emerge as new agents for cancer therapy. This study aimed to investigate the synergistic anti-tumor activity of oncolytic adenovirus armed with IL-24 (ZD55-IL-24) and docetaxel (DTX) on advanced prostate cancer in vitro and in vivo.

METHODS

DU145 prostate cancer cells or nude mice xenografted with DU145 prostate cancer cells were treated by ZD55-IL-24 and DTX alone or in combination.

RESULTS

DTX did not affect ZD55-IL-24 replication and IL-24 expression in DU145 cells. In vitro, the combination of ZD55-IL-24 and DTX showed synergistic inhibitory effects on prostate cancer cell viability and invasion. In vivo, ZD55-IL-24 and DTX synergistically inhibited the growth and activated the apoptosis of DU145 xenografts, accompanied by significantly decreased PARP-1 levels and increased caspase-3 and caspase-8 levels as well as decreased CD31 expression.

CONCLUSION

We reported the synergistic anti-tumor efficacy of ZD55-IL-24 and DTX on prostate cancer. Our results suggest that chemotherapy combined with oncolytic adenovirus mediated gene therapy is a promising strategy for the treatment of advanced prostate cancer.

Adenovirus-mediated IL-24 expression enhances the chemosensitivity of multidrug-resistantgastric 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 in vitro and in vivo. 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 in vitro and SGC7901/CDDP cell xenograft tumors in vivo, 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 in vitro and SGC7901/CDDP xenograft tissues in vivo. Thus, this study indicates that overexpression of IL-24 gene can significantly promote chemosensitivity in MDR phenotype SGC7901/CDDP gastric cancer cells.

Hypalgesia effect of IL-24, a quite new mechanism for IL-24 application in cancer treatment

Tumor suppressor melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) has been extensively regarded as an anti-oncogene; however, that whether IL-24, as a member of IL-10 family, is involved in cancer pain was seldom reported before. In this study, we found that IL-24 mediated by adenovirus could significantly increase the plantar mechanical pain threshold in both operation side and contralateral side of the animal models, which were established by injecting 5×103 Walker 256 rat breast cancer ascitic tumor cells into rats' tibia bone medullary canals; IL-24 could also suppress in vitro Walker 256 cells growth by inducing cell apoptosis. Pathologically, IL-24 could protect bone trabecula and substantia corticalis ossium from being completely destructed. Enzyme-linked immunosorbent assay (ELISA) showed that IL-24 treatment could increase the β-endorphin levels and decrease the IL-6 concentration in plasma of animals. Our study indicated that IL-24 has a potential treatment effect on cancers not only by inhibiting tumor proliferation, but also by the promotion of β-endorphin synthesis, inhibition of IL-6 secretion to relieve cancer pain.

Cancer targeting gene-viro-therapy for pancreatic cancer using oncolytic adenovirus ZD55-IL-24 in immune-competent mice

Cancer targeting gene-viro-therapy (CTGVT) may prove to be an effective treatment for pancreatic cancer (PC). This study was intended to explore the anti-tumor effect of ZD55-IL-24 (oncolytic adenovirus ZD55 harboring IL-24) on PC in immune-competent mice. The expression of gene harbored by oncolytic adenovirus ZD55 in PC cells was detected by reporter-gene assays. The in vitro anti PC ability of ZD55-IL-24 was tested by MTT, crystal violet staining and apoptosis assays. The in vivo anti PC effect of ZD55-IL-24 was further observed in an immune-competent mice model by detecting anti-tumor immunity and induction of apoptosis. The expression of gene harbored by ZD55 in PC cells was significantly higher than that harbored by the replicated-deficient adenovirus, and the amount of gene expression was time-dependent and dose-dependent. Both ZD55-IL-24 and ZD55 inhibited PC cells growth, but the anti-tumor effect of ZD55-IL-24 was significantly stronger than that of ZD55, and the ability of ZD55-IL-24 in inducing PC apoptosis was significantly stronger than that of ZD55. The tumor-forming rate of group ZD55-IL-24 was the lowest, and the tumor-growing rate was also significantly lower than that of group ZD55 in immune-competent PC models. Moreover, ZD55-IL-24 mediated more anti-cancer immunity effects by induction of stronger T-lymphocytes response to PC cells, higher levels of γ-IFN and IL-6 cytokines. ZD55-IL-24-mediated CTGVT could inhibit PC growth not only by inducing oncolysis and apoptosis but enhancing the anti-cancer immune effects by inducing T cell response to PC and up-regulating γ-IFN and IL-6 cytokine in immune-competent mice. This may serve as a candidate therapeutic approach for the treatment of PC.