A dual-regulated oncolytic adenovirus expressing interleukin-24 sensitizes melanoma cells to temozolomide via the induction of apoptosis

Using Weighted Gene Co-Expression Network Analysis to Identify Increased MND1 Expression as a Predictor of Poor Breast Cancer Survival

Objective

We used bioinformatics analysis to identify potential biomarker genes and their relationship with breast cancer (BC).

Materials and Methods

We used a weighted gene co-expression network analysis (WGCNA) to create a co-expression network based on the top 25% genes in the GSE24124, GSE33926, and GSE86166 datasets obtained from the Gene Expression Omnibus. We used the DAVID online platform to perform GO and KEGG pathway enrichment analyses and the Cytoscape CytoHubba plug-in to screen the potential genes. Then, we related the genes to prognostic values in BC using the Oncomine, GEPIA, and Kaplan–Meier Plotter databases. Findings were validated by immunohistochemical (IHC) staining in the Human Protein Atlas and the TCGA-BRCA cohort. LinkedOmics identified the interactive expressions of hub genes. We used UALCAN to evaluate the methylation levels of these hub genes. MethSurv and SurvivalMeth were used to assess the multilevel prognostic value. Finally, we assessed hub gene association with immune cell infiltration using TIMER.

Results

The mRNA levels of MKI67, UBE2C, GTSE1, CCNA2, and MND1 were significantly upregulated in BC, whereas ESR1, THSD4, TFF1, AGR2, and FOXA1 were significantly downregulated. The DNA methylation signature analysis showed a better prognosis in the low-risk group. Further subgroup analyses revealed that MND1 might serve as an independent risk factor for unfavorable BC prognosis. Additionally, MND1 expression levels positively correlate with the immune infiltration statuses of CD4+ T cells, CD8+ T cells, B cells, neutrophils, dendritic cells, and macrophages.

Conclusion

Our results indicate that the ten hub genes may be involved in BC’s carcinogenesis, development, or metastasis, and MND1 may be a potential biomarker and therapeutic target for BC.

SUMO-fusion and autoinduction-based combinatorial approach for enhanced production of bioactive human interleukin-24 in Escherichia coli

High-level production of recombinant human interleukin-24 (IL-24), a multifunctional immunomodulatory cytokine, has been challenging due primarily to its aggregation as inclusion bodies in the bacterial host while persistent poor-expression in the insect/mammalian expression systems. The present study presents a robust, vector-host combination (pE-SUMO-IL24), auto-inducible medium (YNG/M9NG), and a simple purification scheme for soluble, bioactive, and cost-effective production of native-like IL-24 (nIL-24) in Escherichia coli. The final protein yield, following a three-step purification scheme (IMAC, SEC, dialysis), was 98 mg/L in shake-flask culture (with scale-up potential), which was several folds higher than reported earlier. In vitro cytotoxicity assays with HeLa and HCT116 cancer cell lines (performed using different concentrations of nIL-24) and the fluorescence activated cell sorting analysis (FACS) revealed a dose- and concentration-dependent increase in the population of pro-apoptotic cells with concomitant, statistically significant drop in the number of cells existent at G_o/G1-, S-, and G2/M-phases (P < 0.002). The bioactive nIL-24, developed through this study, holds promise for use in further functional characterizations/applications. KEY POINTS: • Yeast SUMO fusion partner at N-terminus for improved solubility of an otherwise insoluble IL-24 in E. coli. • Enhanced cell densities with concomitant several-fold increase in protein yield by lactose-inducible media. • Improved inhibition of cervical and colorectal carcinomas by native-like nIL-24 compared with Met-containing IL. • Heterologous nIL-24 may enable better understanding of the functional intricacies linked up with its unique cancer-specific features. Graphical abstract.

A novel role mediated by adenoviral E1A in suppressing cancer through modulating decorin

Oncolytic adenovirus is an emerging alternative to current therapeutics. The adenoviral E1A, the first protein expressed upon oncolytic adenoviral infection, has been identified as an antitumor agent, but the mechanisms of its tumor inhibition ability are unclear enough. Decorin is ubiquitous in the extracellular matrix (ECM), which regulates multiple functions through interaction with ECM. Here, we intended to explore the effects of adenoviral E1A on the tumor extracellular matrix during gene therapy. We demonstrated that reduced decorin expression was found in patients with lung cancer. The adenoviral E1A or a mutant adenoviral E1A with Rb-binding ability absent (E1A 30-60aa, 120-127aa deletion) could increase the expression of decorin and down-regulate VEGF, two members of tumor ECM, involved in both vasculogenesis and angiogenesis. E1A/mE1A-mediated suppressing the migration and invasion ability of tumor cells was depended on decorin. E1A interacted with decorin directly and induced the proteasomal degradation of VEGF. In addition, E1A or mE1A can inhibit tumor growth in a subcutaneous lung cancer xenograft model. It suggested that decorin might be a crucial mediator among ECM components for adenoviral E1A-mediated antitumor activities. These studies on adenovirus E1A provide a new mechanism for the emerging therapies of tumor gene therapy.

A conditionally replicating adenovirus expressing IL-24 acts synergistically with temozolomide to enhance apoptosis in melanoma cells in vitro

Malignant melanoma is characterized by suppressed apoptosis in tumor cells and high levels of invasion. Temozolomide (TMZ) is one of the most effective single chemotherapeutic agents for patients with malignant melanoma, but resistance develops quickly and frequently. Therapeutic cytokines such as interleukin-24 (IL-24) and conditionally replicating adenoviruses have exhibited promising results as complementary therapies. Thus, the present study hypothesized that a conditionally replicating adenovirus expressing IL-24 combined with TMZ may exhibit increased antitumor activity compared with either treatment alone in melanoma A375 and M14 cell lines in vitro. The present study constructed an E1B-55 gene-deleted conditionally replicating adenovirus expressing the IL-24 gene (ZD55-IL-24). IL-24 was expressed at high levels in melanoma cells infected with ZD55-IL-24 in the presence of TMZ. The combination of ZD55-IL-24 + TMZ induced higher protein expression levels of the proapoptotic proteins B-cell lymphoma-2 (Bcl-2)-like protein 4 and phosphorylated protein, γ-H2A histone family member X (γ-H2AX), and reduced the levels of the antiapoptotic proteins Bcl-2, myeloid cell leukemia-1and nuclear factor-κB compared with either treatment individually. A dose-dependent increase in the cytopathic effects for the combination of ZD55-IL-24 and TMZ was also observed. The data of the present study suggest that the ZD55-IL-24 + TMZ combination induced increased levels of apoptosis, possibly by triggering DNA damage, in melanoma cells in vitro compared with either treatment alone. These findings suggest that this strategy may be a promising approach for the treatment of patients with malignant melanoma.

Mechanism of Action and Applications of Interleukin 24 in Immunotherapy

Interleukin 24 (IL-24) is an important pleiotropic immunoregulatory cytokine, whose gene is located in human chromosome 1q32-33. IL-24's signaling pathways have diverse biological functions related to cell differentiation, proliferation, development, apoptosis, and inflammation, placing it at the center of an active area of research. IL-24 is well known for its apoptotic effect in cancer cells while having no such effect on normal cells. IL-24 can also be secreted by both immune and non-immune cells. Downstream effects of IL-24, after binding to the IL-20 receptor, can occur dependently or independently of the JAK/STAT signal transduction pathway, which is classically involved in cytokine-mediated activities. After exogenous addition of IL-24, apoptosis is induced in tumor cells independently of the JAK/STAT pathway. We have shown that IL-24 binds to Sigma 1 Receptor and this event induces endoplasmic reticulum stress, calcium mobilization, reactive oxygen species generation, p38MAPK activity, and ceramide production. Here we review IL-24's role in autoimmunity, infectious disease response, wound repair, and vascular disease. Detailed understanding of the pleiotropic roles of IL-24 signaling can assist in the selection of more accurate therapeutic approaches, as well as targeting of appropriate cell types in treatment strategy development, and ultimately achieve desired therapeutic effects.

Trial Watch-Oncolytic viruses and cancer therapy

Oncolytic virotherapy relies on the administration of non-pathogenic viral strains that selectively infect and kill malignant cells while favoring the elicitation of a therapeutically relevant tumor-targeting immune response. During the past few years, great efforts have been dedicated to the development of oncolytic viruses with improved specificity and potency. Such an intense wave of investigation has culminated this year in the regulatory approval by the US Food and Drug Administration (FDA) of a genetically engineered oncolytic viral strain for use in melanoma patients. Here, we summarize recent preclinical and clinical advances in oncolytic virotherapy.

Combined therapy of oncolytic adenovirus and temozolomide enhances lung cancer virotherapy in vitro and in vivo

Oncolytic adenoviruses (OAds) are very promising for the treatment of lung cancer. However, OAd-based monotherapeutics have not been effective during clinical trials. Therefore, the effectiveness of virotherapy must be enhanced by combining OAds with other therapies. In this study, the therapeutic potential of OAd in combination with temozolomide (TMZ) was evaluated in lung cancer cells in vitro and in vivo. The combination of OAd and TMZ therapy synergistically enhanced cancer cell death; this enhanced cancer cell death may be explained via three related mechanisms: apoptosis, virus replication, and autophagy. Autophagy inhibition partially protected cancer cells from this combined therapy. This combination significantly suppressed the growth of subcutaneous H441 lung cancer xenograft tumors in athymic nude mice. In this study, we have provided an experimental rationale to test OAds in combination with TMZ in a lung cancer clinical trial.

Novel oncolytic adenovirus sensitizes renal cell carcinoma cells to radiotherapy via mitochondrial apoptotic cell death

Renal cell carcinoma is the most frequent kidney malignancy and patients with metastatic disease have a poor prognosis. Suppressed apoptosis and marked invasiveness are distinctive features of renal cell carcinoma. In the present study, a dual‑regulated oncolytic adenovirus expressing the interluekin (IL)‑24 gene (Ki67‑ZD55‑IL‑24) was constructed utilizing the Ki67 promoter to replace the native viral promoter of the E1A gene. Whether the combination of Ki67‑ZD55‑IL‑24‑mediated gene virotherapy and radiotherapy produced increased cytotoxicity in renal cell carcinoma cells via mitochondrial apoptotic cell death was investigated. The data indicated that this novel strategy has the potential to be further developed into an effective approach to treat renal cell carcinoma. The results showed that the combination of Ki67‑ZD55‑IL‑24 and radiotherapy significantly enhanced anti‑tumour activity via increasing the induction of apoptosis in melanoma cells compared with the other agents.

Enhanced antitumor efficacy of a novel oncolytic adenovirus combined with temozolomide in the treatment of melanoma in vivo

PURPOSE

The aim of this study was to investigate the effect of Ki67-ZD55-IL-24 with temozolomide (TMZ) against melanoma in mice.

METHODS

Seventy-eight mice with subcutaneous injection of A375 cells (2 × 10(6)) into the right flank were randomized to receive phosphate buffered saline (PBS), Ki67-ZD55, Ki67-ZD55-IL-24, TMZ, TMZ + Ki67-ZD55, and TMZ + Ki67-ZD55-IL-24. Six mice were killed in each group 10 days after intervention for detecting IL-24 mRNA and protein expression. The remaining mice were monitored to draw the body weight change curve and tumor growth curve, and killed 30 days after intervention. Tumors were excised and weighted. The morphology of tumor tissues was determined by hematoxylin and eosin (HE) staining, and the apoptosis index and rate of apoptotic cells were determined by TUNEL assay and AnnexinV-FITC/PI double staining, respectively.

RESULTS

The Ki67-ZD55-IL-24-treated group generated much more reactive oxygen species than the untreated group. There was no significant difference in IL-24 expression between Ki67-ZD55-IL-24 and TMZ + Ki67-ZD55-IL-24 groups. Immunohistochemical analysis and Western blot revealed that both the Ki67-ZD55 and Ki67-ZD55-IL-24 could significantly reduce the expression of MGMT. Toxicity assessments demonstrated that mice in the three groups that received TMZ exhibited significant body weight loss following treatment. HE staining showed that TMZ + Ki67-ZD55-IL-24 group had much fewer karyokinesis in the tumors, compared with other groups. The apoptosis index of tumor tissues and the rate of apoptotic cells were significantly higher in TMZ + Ki67-ZD55-IL-24 group than in other groups (all P < 0.05).

CONCLUSIONS

These findings indicate this novel strategy holds promising potentials for treatment of malignant melanoma.

Trial Watch:: Oncolytic viruses for cancer therapy

Oncolytic viruses are natural or genetically modified viral species that selectively infect and kill neoplastic cells. Such an innate or exogenously conferred specificity has generated considerable interest around the possibility to employ oncolytic viruses as highly targeted agents that would mediate cancer cell-autonomous anticancer effects. Accumulating evidence, however, suggests that the therapeutic potential of oncolytic virotherapy is not a simple consequence of the cytopathic effect, but strongly relies on the induction of an endogenous immune response against transformed cells. In line with this notion, superior anticancer effects are being observed when oncolytic viruses are engineered to express (or co-administered with) immunostimulatory molecules. Although multiple studies have shown that oncolytic viruses are well tolerated by cancer patients, the full-blown therapeutic potential of oncolytic virotherapy, especially when implemented in the absence of immunostimulatory interventions, remains unclear. Here, we cover the latest advances in this active area of translational investigation, summarizing high-impact studies that have been published during the last 12 months and discussing clinical trials that have been initiated in the same period to assess the therapeutic potential of oncolytic virotherapy in oncological indications.

Potent anti-tumour activity of a novel conditionally replicating adenovirus for melanoma via inhibition of migration and invasion

Background:

Conditionally replicating adenoviruses (CRAds) represent a novel class of oncological therapeutic agents. One strategy to ensure tumour targeting is to place the essential viral genes under the control of tumour-specific promoters. Ki67 has been selected as a cancer gene therapy target, as it is expressed in most malignant cells but is barely detectable in most normal cells. This study aimed to investigate the effects of a Ki67 promoter-controlled CRAd (Ki67-ZD55-IL-24) on the proliferation and apoptosis of melanoma cells.

Methods:

Melanoma cells were independently treated with Ki67-ZD55-IL-24, ZD55-IL-24, Ki67-ZD55, and ZD55-EGFP. The cytotoxic potential of each treatment was assessed using cell viability measurements. Cell migration and invasion were assayed using cell migration and invasion assays. Apoptosis was assayed using the annexin V-FITC assay, western blotting, reverse transcriptase PCR (RT–PCR), haematoxylin and eosin (H&E) staining, and the TUNEL assay.

Results:

Our results showed that Ki67-ZD55-IL-24 had significantly enhanced anti-tumour activity as it more effectively induced apoptosis in melanoma cells than the other agents. Ki67-ZD55-IL-24 also caused the most significant inhibition of cell migration and invasion of melanoma cells. Furthermore, apoptosis was induced more effectively in melanoma xenografts in nude mice.

Conclusions:

This strategy holds promising potential for the further development of an effective approach to treat malignant melanoma.

Molecular targets and signaling pathways regulated by interleukin (IL)-24 in mediating its antitumor activities

Cancer remains a major health issue in the world and the effectiveness of current therapies is limited resulting in disease recurrence and resistance to therapy. Therefore to overcome disease recurrence and have improved treatment efficacy there is a continued effort to develop and test new anticancer drugs that are natural or synthetic - (conventional chemotherapeutics, small molecule inhibitors) and biologic (antibody, tumor suppressor genes, oligonucleotide) product. In parallel, efforts for identifying molecular targets and signaling pathways to which cancer cells are "addicted" are underway. By inhibiting critical signaling pathways that is crucial for cancer cell survival, it is expected that the cancer cells will undergo a withdrawal symptom akin to "de-addiction" resulting in cell death. Thus, the key for having an improved and greater control on tumor growth and metastasis is to develop a therapeutic that is able to kill tumor cells efficiently by modulating critical signaling pathways on which cancer cells rely for their survival.Currently several small molecule inhibitors targeted towards unique molecular signaling pathways have been developed and tested in the clinic. Few of these inhibitors have shown efficacy while others have failed. Thus, targeting a single molecule or pathway may be insufficient to completely block cancer cell proliferation and survival. It is therefore important to identify and test an anticancer drug that can inhibit multiple signaling pathways in a cancer cell, control growth of both primary and metastatic tumors and is safe.One biologic agent that has the characteristics of serving as a potent anticancer drug is interleukin (IL)-24. IL-24 suppresses multiple signaling pathways in a broad-spectrum of human cancer cells leading to tumor cell death, inhibition of tumor angiogenesis and metastasis. Additionally, combining IL-24 with other therapies demonstrated additive to synergistic antitumor activity. Clinical testing of IL-24 as a gene-based therapeutic for the treatment of solid tumors demonstrated that IL-24 is efficacious and is safe. The unique features of IL-24 support its further development as an anticancer drug for cancer treatment.In this review we summarize the current understanding on the molecular targets and signaling pathways regulated by IL-24 in mediating its anticancer activity.

The efficacy of combination therapy using adeno-associated virus-mediated co-expression of apoptin and interleukin-24 on hepatocellular carcinoma

Multigene-based combination therapy is an effective practice in cancer gene therapy. Apoptin is a chicken anemia virus-derived, p53-independent, Bcl-2-insensitive apoptotic protein with the ability to specifically induce apoptosis in various human tumor cells. Interleukin-24 (IL-24) displays ubiquitous antitumor property and tumor-specific killing activity. Adeno-associated virus (AAV) is a promising gene delivery vehicle due to its advantage of low pathogenicity and long-term gene expression. In this study, we assessed the efficacy of combination therapy using AAV-mediated co-expression of apoptin and interleukin-24 on hepatocellular carcinoma in vitro and in vivo. Our results showed that AAV-mediated co-expression of IL-24 and apoptin significantly suppressed the growth and induced the apoptosis of HepG2 cells in vitro. Furthermore, AAV-mediated combined treatment of IL-24 and apoptin significantly suppressed tumor growth and induced apoptosis of tumor cells in xenograft nude mice. These data suggest that AAV vectors that co-express apoptin and IL-24 have great potential in cancer gene therapy.