CEA promoter-regulated oncolytic adenovirus-mediated Hsp70 expression in immune gene therapy for pancreatic cancer. Cancer Lett. 2012;319:154-163. [PMID: 22261331 DOI: 10.1016/j.canlet.2012.01.009]

Synthesis of flower-like ZnO nanoparticles for label-free point of care detection of carcinoembryonic antigen

In this work, flower-like ZnO nanoparticles (ZnONPs) were synthesized using zinc nitrate (Zn(NO3)2 6H2O) as a precursor with KOH. The morphology of the ZnONPs was controlled by varying the synthesis temperature at 50, 75 and 95 °C. The morphology and structure of ZnONPs were characterized using Scanning Electron Microscopy, and X-Ray Diffraction and Brunauer-Emmett Teller analysis. ZnONPs were successfully synthesized by a simple chemical precipitation method. A synthesis temperature of 75 °C produced the most suitable flower-like ZnONPs, which were combined with graphene nanoplatelets to develop a label-free electrochemical immunosensor for the detection of the colon cancer biomarker carcinoembryonic antigen in human serum. Under optimum conditions, the developed immunosensor showed a linear range of 0.5-10.0 ng mL-1 with a limit of detection of 0.44 ng mL-1. The label-free electrochemical immunosensor exhibited good selectivity, reproducibility, and repeatability, and recoveries were excellent. The immunosensor is used with a Near-Field Communication potentiostat connected to a smartphone to facilitate point-of-care cancer detection in low-resource locations.

Tumor‐targeted fluorescence labeling systems for cancer diagnosis and treatment

Conventional imaging techniques are available for clinical identification of tumor sites. However, detecting metastatic tumor cells that are spreading from primary tumor sites using conventional imaging techniques remains difficult. In contrast, fluorescence‐based labeling systems are useful tools for detecting tumor cells at the single‐cell level in cancer research. The ability to detect fluorescent‐labeled tumor cells enables investigations of the biodistribution of tumor cells for the diagnosis and treatment of cancer. For example, the presence of fluorescent tumor cells in the peripheral blood of cancer patients is a predictive biomarker for early diagnosis of distant metastasis. The elimination of fluorescent tumor cells without damaging normal tissues is ideal for minimally invasive treatment of cancer. To capture fluorescent tumor cells within normal tissues, however, tumor‐specific activated target molecules are needed. This review focuses on recent advances in tumor‐targeted fluorescence labeling systems, in which indirect reporter labeling using tumor‐specific promoters is applied to fluorescence labeling of tumor cells for the diagnosis and treatment of cancer. Telomerase promoter‐dependent fluorescence labeling using replication‐competent viral vectors produces fluorescent proteins that can be used to detect and eliminate telomerase‐positive tumor cells. Tissue‐specific promoter‐dependent fluorescence labeling enables identification of specific tumor cells. Vimentin promoter‐dependent fluorescence labeling is a useful tool for identifying tumor cells that undergo epithelial–mesenchymal transition (EMT). The evaluation of tumor cells undergoing EMT is important for accurately assessing metastatic potential. Thus, tumor‐targeted fluorescence labeling systems represent novel platforms that enable the capture of tumor cells for the diagnosis and treatment of cancer.

An Immunosensor Using Electroactive COF as Signal Probe for Electrochemical Detection of Carcinoembryonic Antigen

Two kinds of two-dimensional (2D) covalent-organic frameworks (COF) were used to construct a sandwich-type electrochemical immunosensor for a proof-of-concept study. Vinyl-functionalized COFTab-Dva could be linked with Ab1 by the thiol-ene "click" reaction. Electroactive COFTFPB-Thi was modified with gold nanoparticles (AuNPs) to ensure the successful connection with Ab2 through Au-S bond. Meanwhile, electroactive COFTFPB-Thi was used to as signal probe to realize both the detection of carcinoembryonic antigen (CEA) and the amplification of detection signal. In detection process of the sandwich-type electrochemical immunosensor, glassy carbon electrode (GCE) was modified with 2D COFTab-Dva first then connected with Ab1 by the thiol-ene "click" reaction, next quantitative CEA was captured, followed by specificially capturing signal probe of Ab2/AuNPs/COFTFPB-Thi where AuNPs acted as nanocarriers of Ab2 and COFTFPB-Thi served as the signal producers. As the amount of CEA was increased, the amount of signal probe captured to the electrode was also increased, and the peak signal intensity of the redox reaction of COFTFPB-Thi was enhanced accordingly. Thus, the quantitative detection of CEA could be realized according to the peak signal intensity of electroactive COFTFPB-Thi. The electrochemical immunosensor owned wide detection range of 0.11 ng/mL-80 ng/mL, low detection limit of 0.034 ng/mL and good practicability. This study opens up a new revelation for quantitative detection of CEA using electroactive COF as enhanced signal probe.

Current strategies in engaging oncolytic viruses with antitumor immunity

Oncolytic virotherapy has produced promising yet limited results in preclinical and clinical studies. Besides direct oncolytic activity, a significant therapeutic mechanism of oncolytic virotherapy is the induction of tumor-specific immunity. Consequently, the efficacy of oncolytic viruses can be improved by the insertion of immune stimulator genes and rational combinatorial therapy with other immunotherapies. This article reviews recent efforts on arming oncolytic viruses with a variety of immune stimulator molecules, immune cell engagers, and other immune potentiating molecules. We outline what is known about the mechanisms of action and the corresponding results. The review also discusses recent preclinical and clinical studies of combining oncolytic virotherapy with immune-checkpoint inhibitors and the role of oncolytic virotherapy in changing the tumor microenvironment.

Immuno-Oncolytic Viruses: Emerging Options in the Treatment of Colorectal Cancer

Colorectal cancer is the third most common neoplasm in the world and the third leading cause of cancer-related deaths in the USA. A safer and more effective therapeutic intervention against this malignant carcinoma is called for given the limitations and toxicities associated with the currently available treatment modalities. Immuno-oncolytic or oncolytic virotherapy, the use of viruses to selectively or preferentially kill cancer cells, has emerged as a potential anticancer treatment modality. Oncolytic viruses act as double-edged swords against the tumors through the direct cytolysis of cancer cells and the induction of antitumor immunity. A number of such viruses have been tested against colorectal cancer, in both preclinical and clinical settings, and many have produced promising results. Oncolytic virotherapy has also shown synergistic antitumor efficacy in combination with conventional treatment regimens. In this review, we describe the status of this therapeutic approach against colorectal cancer at both preclinical and clinical levels. Successes with and the challenges of using oncolytic viruses, both as monotherapy and in combination therapy, are also highlighted.

Oncolytic Adenovirus CD55-Smad4 Suppresses Cell Proliferation, Metastasis, and Tumor Stemness in Colorectal Cancer by Regulating Wnt/β-Catenin Signaling Pathway

During the past few decades, colorectal cancer (CRC) incidence and mortality have significantly increased, and CRC has become the leading cause of cancer-related death worldwide. Thus, exploring novel effective therapies for CRC is imperative. In this study, we investigated the effect of oncolytic adenovirus CD55-Smad4 on CRC cell growth. Cell viability assay, animal experiments, flow cytometric analysis, cell migration, and invasion assays, and Western blotting were used to detect the proliferation, apoptosis, migration, and invasion of CRC cells. The oncolytic adenovirus CD55-Smad4 was successfully constructed and effectively suppressed CRC cell proliferation in vivo and in vitro. Notably, CD55-Smad4 activated the caspase signaling pathway, inducing the apoptosis of CRC cells. Additionally, the generated oncolytic adenovirus significantly suppressed migration and invasion of CRC cells by overexpressing Smad4 and inhibiting Wnt/β-catenin/epithelial-mesenchymal transition (EMT) signaling pathway. Moreover, CRC cells treated with CD55-Smad4 formed less and smaller spheroid colonies in serum-free culture than cells in control groups, suggesting that CD55-Smad4 suppressed the stemness of CRC cells by inhibiting the Wnt/β-catenin pathway. Together, the results of this study provide valuable information for the development of a novel strategy for cancer-targeting gene-virotherapy and provide a deeper understanding of the critical significance of Smad4 in gene therapy of CRC.

Hsp70 in cancer: A double agent in the battle between survival and death

The heat shock protein (Hsps) superfamily, also known as molecular chaperones, are highly conserved and present in all living organisms and play vital roles in protein fate. The HspA1A (Hsp70-1), called Hsp70 in this review, is expressed at low or undetectable levels in most unstressed normal cells, but numerous studies have shown that diverse types of tumor cells express Hsp70 at the plasma membrane that leads to resistance to programmed cell death and tumor progression. Hsp70 is released into the extracellular milieu in three forms including free soluble, complexed with cancer antigenic peptides, and exosome forms. Therefore, it seems to be a promising therapeutic target in human malignancies. However, a great number of studies have indicated that both intracellular and extracellular Hsp70 have a dual function. A line of evidence presented that intracellular Hsp70 has a cytoprotective function via suppression of apoptosis and lysosomal cell death (LCD) as well as that extracellular Hsp70 can promote tumorigenesis and angiogenesis. Other evidence showed intracellular Hsp70 can promote apoptosis and membrane-associated/extracellular Hsp70 can elicit antitumor innate and adaptive immune responses. Given the contradictory functions, as a "double agent," could Hsp70 be a promising tool in the future of targeted cancer therapies? To answer this question, in this review, we will discuss the functions of Hsp70 in cancers besides inhibition and stimulation strategies for targeting Hsp70 along with their challenges.

Oncolytic Adenovirus Expressing ST13 Increases Antitumor Effect of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Against Pancreatic Ductal Adenocarcinoma

Oncolytic adenoviruses (OAds) are promising agents for cancer therapy, representing a novel therapeutic strategy for pancreatic ductal adenocarcinoma (PDAC). However, there are challenges associated with the successful use of an OAd alone, involving the security of the viral vector and screening of an effective antitumor gene. In the present study, a novel OAd CD55-ST13-tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was constructed in which the dual therapeutic genes ST13 and TRAIL were inserted, featuring the carcinoembryonic antigen (CEA) as a promoter to control E1A and deletion of the 55 kDa E1B gene. ST13, known as a colorectal cancer suppressor gene, exhibited lower expression in PDAC than in tumor-adjacent tissues and was associated with poor prognosis in PDAC patients. In vitro studies demonstrated that CD55-ST13-TRAIL was effective in promoting the expression of ST13 and TRAIL in CEA-positive pancreatic cancer cells. Moreover, CD55-ST13-TRAIL exhibited a synergistic effect toward tumor cell death compared with CD55-ST13 alone or CD55-TRAIL alone, and inhibited tumor cell proliferation and induced cell apoptosis dependent on caspase pathways in PDAC cells. Furthermore, xenograft experiments in a mouse model indicated that CD55-ST13-TRAIL significantly inhibited tumor growth and improved the survival of animals with xenografts. The findings demonstrate that oncolytic virotherapy under the control of the promoter CEA enables safe and efficient treatment of PDAC, and suggest that it represents a promising candidate for the treatment of metastatic diseases.

Oncolytic viruses for cancer immunotherapy

In this review, we discuss the use of oncolytic viruses in cancer immunotherapy treatments in general, with a particular focus on adenoviruses. These serve as a model to elucidate how versatile viruses are, and how they can be used to complement other cancer therapies to gain optimal patient benefits. Historical reports from over a hundred years suggest treatment efficacy and safety with adenovirus and other oncolytic viruses. This is confirmed in more contemporary patient series and multiple clinical trials. Yet, while the first viruses have already been granted approval from several regulatory authorities, room for improvement remains.

As good safety and tolerability have been seen, the oncolytic virus field has now moved on to increase efficacy in a wide array of approaches. Adding different immunomodulatory transgenes to the viruses is one strategy gaining momentum. Immunostimulatory molecules can thus be produced at the tumor with reduced systemic side effects. On the other hand, preclinical work suggests additive or synergistic effects with conventional treatments such as radiotherapy and chemotherapy. In addition, the newly introduced checkpoint inhibitors and other immunomodulatory drugs could make perfect companions to oncolytic viruses. Especially tumors that seem not to be recognized by the immune system can be made immunogenic by oncolytic viruses. Logically, the combination with checkpoint inhibitors is being evaluated in ongoing trials. Another promising avenue is modulating the tumor microenvironment with oncolytic viruses to allow T cell therapies to work in solid tumors.

Oncolytic viruses could be the next remarkable wave in cancer immunotherapy.

Constructing a Novel Hypoxia-Inducible Bidirectional shRNA Expression Vector for Simultaneous Gene Silencing in Colorectal Cancer Gene Therapy

BACKGROUND

Nonspecific siRNA expression limits its application in cancer gene therapy. Therefore, a tightly regulated and reversibly inducible RNAi system is required to conditionally control the gene expression. This investigation aims at constructing a hypoxia/colorectal tumor dual-specific bidirectional short hairpin RNA (shRNA) expression vector.

MATERIALS AND METHODS

First, carcinoma embryonic antigen (CEA) promoter designed in two directions. Then, pRNA-bipHRE-CEA vector was constructed by insertion of the vascular endothelial growth factor enhancer between two promoters for hypoxic cancer-specific gene expression. To confirm the therapeutic effect of the dual-specific vector, two shRNA oligonucleotides were inserted in the downstream of each promoter. QRT-polymerase chain reaction and western blot assays were performed to estimate the mRNA and protein expression levels.

RESULTS

Both mRNA and protein levels were significantly reduced (50%-60%) in the hypoxic colorectal cancer-treated cells when compared with the controls.

CONCLUSION

The novel bidirectional hypoxia-inducible shRNA expression vector may be efficient in colorectal cancer-specific gene therapy.

Promoter-Operating Targeted Expression of Gene Therapy in Cancer: Current Stage and Prospect

The technique of targeted expression of interesting genes, including distinct delivery systems and specific gene promoter-operating expression, is an important strategy for gene therapy against cancers. Up to now, extensive literature documented the efficacy of distinct delivery systems, such as the liposome system, nano-particle system, polyetherimide (PEI) system, and so on, in cancer gene therapy. However, a related document on the potential value of using a specific gene promoter, such as a tumor suppressor, in cancer gene therapy was still scary. The main obstacle might be that the selection of an ideal gene promoter to operate interesting gene expression in cancer gene therapy is still not fully understood. Therefore, many efforts need to be done in order to make it a real power tool for the human clinical treatment of cancer patients. The purpose of this review is to clarify the current state and some problematics in development of promoter-operating targeted expression of interesting genes and highlight its potential in cancer gene therapy.

Simultaneous overexpression of miR-126 and miR-34a induces a superior antitumor efficacy in pancreatic adenocarcinoma

Background

Pancreatic adenocarcinoma (PAC) is one of the most fatal cancers due to its high degree of malignancy, increasing incidence, high mortality, and unsatisfactory treatment efficacy. Evidence has suggested that numerous microRNAs (miRNAs), including miR-126 and miR-34a, have potent tumor-suppressing effects on PAC, implicating a possible application of miRNA in tumor therapy. However, the therapeutic effect of a single miRNA on pancreatic cancer is limited.

Methods

We simultaneously delivered miR-126 and miR-34a into PAC cells by a carcinoembryonic antigen promoter-driven oncolytic adenovirus (AdCEAp-miR126/34a), and examined the antitumor efficacy of the therapeutic system in in vitro and in vivo experiments.

Results

In vitro cytological experiments found that the expression levels of miR-126 and miR-34a were specifically increased in the AdCEAp-miR126/34a-infected PAC cells, and the antitumor efficacy was enhanced in aspects of cancer cell viability, migration, invasion, and apoptosis, by synergistically combining the antitumor effects of overexpressed miR-126 and miR-34a and the oncolytic effect of viral replication specifically in PAC cells. The expression levels of miR-126 target genes (vascular endothelial growth factor-A and SOX2) and miR-34a target genes (cyclin D1, E2F1, and Bcl-2) were markedly decreased in the PAC cells after being infected with AdCEAp-miR126/34a. Notable suppression of the therapeutic system on tumor growth was also proven in established PAC xenograft tumor models in nude mice, which demonstrated that the combination of miR-126 and miR-34a exerts more effective antitumor outcomes than a single miRNA.

Conclusion

The therapeutic system co-expressing miR-126 and miR-34a mediated by oncolytic adenovirus is a promising system for PAC target therapy.

Telomerase-specific oncolytic adenovirus expressing TRAIL suppresses peritoneal dissemination of gastric cancer

Peritoneal dissemination is the most common condition of metastasis in gastric cancer. The survival duration of a patient with advanced stage gastric cancer, may be improved by gene therapy. In this study, we used an oncolytic adenovirus vector (Ad/TRAIL-E1) that expresses both the TRAIL and E1A genes under the control of a tumor-specific promoter. We evaluated the anti-tumor effect of Ad/TRAIL-E1 on gastric cancer cells in vitro, as well as in vivo in a xenograft peritoneal carcinomatosis mouse model. Our data showed that Ad/TRAIL-E1 induced TRAIL-mediated apoptosis in gastric cancer cell lines, but not in the normal cell lines. In addition, Ad/TRAIL-E1 significantly inhibited peritoneal metastasis and prolonged the survival of mice without treatment-related toxicity. Therefore, tumor-specific TRAIL expression from an oncolytic adenovirus vector may provide a novel therapeutic approach for the treatment of advance stage gastric cancer with peritoneal dissemination.

HSP70-based anti-cancer immunotherapy

Heat shock protein 70, (Hsp70) constitutes a powerful system of cytoprotection in all organisms studied to date. Exerting such activity, Hsp70 rescues cancer cells from antitumor therapy, posing a great challenge for oncologists. In contrast to its protective action, Hsp70 was found to be released from cancer cells, prompting cytotoxic lymphocytes to target and kill the tumor. A great number of vaccines have been developed on the basis of the ability of Hsp70 to present tumor antigen or to elevate the sensitivity of cancer cells to cytotoxic lymphocytes. In this commentary, we consider novel data on the employment of pure Hsp70 in the therapy of glioma and melanoma malignancies. We show that intratumorally delivered Hsp70 penetrates cancer cells and pulls its intracellular analog outside of the cell. This displacement may activate cells, constituting both innate and adaptive immunity. In vivo delivery of Hsp70 was found to inhibit tumor growth and to extend survival. The technology of intratumoral injection of pure Hsp70 passed through preclinical trials and was investigated in clinics for children with brain cancer; the results show the safety and feasibility of a new approach.

Viro-immune therapy: A new strategy for treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an almost uniformly lethal disease with less than 5% survival at five years. This is largely due to metastatic disease, which is already present in the majority of patients when diagnosed. Even when the primary cancer can be removed by radical surgery, local recurrence occurs within one year in 50%-80% of cases. Therefore, it is imperative to develop new approaches for the treatment of advanced cancer and the prevention of recurrence after surgery. Tumour-targeted oncolytic viruses (TOVs) have become an attractive therapeutic agent as TOVs can kill cancer cells through multiple mechanisms of action, especially via virus-induced engagement of the immune response specifically against tumour cells. To attack tumour cells effectively, tumour-specific T cells need to overcome negative regulatory signals that suppress their activation or that induce tolerance programmes such as anergy or exhaustion in the tumour microenvironment. In this regard, the recent breakthrough in immunotherapy achieved with immune checkpoint blockade agents, such as anti-cytotoxic T-lymphocyte-associate protein 4, programmed death 1 (PD-1) or PD-L1 antibodies, has demonstrated the possibility of relieving immune suppression in PDAC. Therefore, the combination of oncolytic virotherapy and immune checkpoint blockade agents may synergistically function to enhance the antitumour response, lending the opportunity to be the future for treatment of pancreatic cancer.

Targeted Hsp70 expression combined with CIK-activated immune reconstruction synergistically exerts antitumor efficacy in patient-derived hepatocellular carcinoma xenograft mouse models

The patient-derived tumor xenograft (PDTX) models can reproduce a similar natural genetic background and similar biological behaviors to tumor cells in patients, which is conducive to the assessment of personalized cancer treatment. In this study, to verify the targeting and effectiveness of the therapeutic strategy using a Survivin promoter-regulated oncolytic adenovirus expressing Hsp70, the PDTX models of hepatocellular carcinoma (HCC) were established in nude mice and the cytokine-induced killer (CIK) cells were intravenously infused into mice to partially reconstruct the mouse immune function. The results demonstrated that, either the immune anti-tumor effect caused by CIK cell infusion or the oncolytic effect generated by oncolytic adenovirus replication was very limited. However, the synergistic tumor inhibitory effect was significantly enhanced after treatments with oncolytic adenovirus expressing Hsp70 combined with CIK cells. Oncolytic adenovirus mediated the specific expression of Hsp70 in cancer tissues allowed the CIK chemotaxis, and induce the infiltration of CD3+ T cells in tumor stroma, thereby exhibiting anti-tumor activity. The anti-tumor effect was more effective for the highly malignant tumor xenografts with highly Survivin expression. This strategy can synergistically activate multiple anti-tumor mechanisms and exert effective anti-tumor activities that have a significant inhibitory effect against the growth of HCC xenografts.

Tissue Specific Promoters in Colorectal Cancer

Colorectal carcinoma is the third most prevalent cancer in the world. In the most advanced stages, the use of chemotherapy induces a poor response and is usually accompanied by other tissue damage. Significant progress based on suicide gene therapy has demonstrated that it may potentiate the classical cytotoxic effects in colorectal cancer. The inconvenience still rests with the targeting and the specificity efficiency. The main target of gene therapy is to achieve an effective vehicle to hand over therapeutic genes safely into specific cells. One possibility is the use of tumor-specific promoters overexpressed in cancers. They could induce a specific expression of therapeutic genes in a given tumor, increasing their localized activity. Several promoters have been assayed into direct suicide genes to cancer cells. This review discusses the current status of specific tumor-promoters and their great potential in colorectal carcinoma treatment.

Specific Colon Cancer Cell Cytotoxicity Induced by Bacteriophage E Gene Expression under Transcriptional Control of Carcinoembryonic Antigen Promoter

Colorectal cancer is one of the most prevalent cancers in the world. Patients in advanced stages often develop metastases that require chemotherapy and usually show a poor response, have a low survival rate and develop considerable toxicity with adverse symptoms. Gene therapy may act as an adjuvant therapy in attempts to destroy the tumor without affecting normal host tissue. The bacteriophage E gene has demonstrated significant antitumor activity in several cancers, but without any tumor-specific activity. The use of tumor-specific promoters may help to direct the expression of therapeutic genes so they act against specific cancer cells. We used the carcinoembryonic antigen promoter (CEA) to direct E gene expression (pCEA-E) towards colon cancer cells. pCEA-E induced a high cell growth inhibition of human HTC-116 colon adenocarcinoma and mouse MC-38 colon cancer cells in comparison to normal human CCD18co colon cells, which have practically undetectable levels of CEA. In addition, in vivo analyses of mice bearing tumors induced using MC-38 cells showed a significant decrease in tumor volume after pCEA-E treatment and a low level of Ki-67 in relation to untreated tumors. These results suggest that the CEA promoter is an excellent candidate for directing E gene expression specifically toward colon cancer cells.

Photoimmunotherapy Inhibits Tumor Recurrence After Surgical Resection on a Pancreatic Cancer Patient-Derived Orthotopic Xenograft (PDOX) Nude Mouse Model

BACKGROUND

Photoimmunotherapy (PIT) uses a target-specific photosensitizer based on a near-infrared (NIR) phthalocyanine dye, IR700, to induce tumor necrosis after irradiation with NIR light to kill cancer cells, such as those that remain after surgery. The purpose of the present study was to sterilize the surgical bed after pancreatic cancer resection with PIT in carcinoembryonic antigen (CEA)-expressing, patient-derived, orthotopic xenograft (PDOX) nude mouse models.

METHODS

After confirmation of tumor engraftment, mice were randomized to two groups: bright light surgery (BLS)-only and BLS + PIT. Each treatment arm consisted of seven tumor-bearing mice. BLS was performed under standard bright-field with an MVX10 long-working distance, high-magnification microscope on all mice. For BLS + PIT, anti-CEA antibody conjugated with IR700 (anti-CEA-IR700) (50 µg) was injected intravenously in all mice 24 h before surgery. After the surgery, the resection bed was then irradiated with a red-light-emitting diode at 690 ± 5 nm with a power density of 150 mW/cm(2).

RESULTS

Anti-CEA-IR700 labelled and illuminated the pancreatic cancer PDOX. Minimal residual cancer of the PDOX was detected by fluorescence after BLS. The local recurrence rate was 85.7 % for BLS-only and 28.6 % for BLS + PIT-treated mice (p = 0.05). The average recurrent tumor weight was 1149.0 ± 794.6 mg for BLS-only and 210.8 ± 336.9 mg for BLS + PIT-treated mice (p = 0.015).

CONCLUSION

Anti-CEA-IR700 was able to label and illuminate a pancreatic cancer PDOX nude mouse model sufficiently for PIT. PIT reduced recurrence by eliminating remaining residual cancer cells after BLS.

Survivin promoter-regulated oncolytic adenovirus with Hsp70 gene exerts effective antitumor efficacy in gastric cancer immunotherapy

Gene therapy is a promising adjuvant therapeutic strategy for cancer treatment. To overcome the limitations of current gene therapy, such as poor transfection efficiency of vectors, low levels of transgene expression and lack of tumor targeting, the Survivin promoter was used to regulate the selective replication of oncolytic adenovirus in tumor cells, and the heat shock protein 70 (Hsp70) gene was loaded as the anticancer transgene to generate an AdSurp-Hsp70 viral therapy system. The efficacy of this targeted immunotherapy was examined in gastric cancer. The experiments showed that the oncolytic adenovirus can selectively replicate in and lyse the Survivin-positive gastric cancer cells, without significant toxicity to normal cells. AdSurp-Hsp70 reduced viability of cancer cells and inhibited tumor growth of gastric cancer xenografts in immuno-deficient and immuno-reconstruction mouse models. AdSurp-Hsp70 produced dual antitumor effects due to viral replication and high Hsp70 expression. This therapeutic system used the Survivin promoter-regulated oncolytic adenovirus vector to mediate targeted expression of the Hsp70 gene and ensure safety and efficacy for subsequent gene therapy programs against a variety of cancers.

Oncolytic viral therapy for pancreatic cancer: current research and future directions

The development of targeted agents and chemotherapies for pancreatic cancer has only modestly affected clinical outcome and not changed 5-year survival. Fortunately the genetic and molecular mechanisms underlying pancreatic cancer are being rapidly uncovered and are providing opportunities for novel targeted therapies. Oncolytic viral therapy is one of the most promising targeted agents for pancreatic cancer. This review will look at the current state of the development of these self-replicating nanoparticles in the treatment of pancreatic cancer.

Cancer vaccines targeting carcinoembryonic antigen: state-of-the-art and future promise

Concurrent with the US FDA's approval of the first therapeutic cancer vaccine, and supported by mounting clinical evidence indicating that targeting carcinoembryonic antigen (CEA) can safely overcome pre-existing tolerance, a multitude of novel CEA cancer vaccines are now in various stages of development. Since cancer-driven immune suppression often limits the efficacy of vaccines, numerous strategies are being examined in both preclinical and clinical settings to overcome immunosuppressive elements, including the combined use of vaccines with certain chemotherapies, immune checkpoint inhibitors, small-molecule targeted therapies and radiation. This review discusses the current state and future direction of therapeutic cancer vaccines targeting CEA, based on advances achieved over the last 5 years.

Viral therapy for pancreatic cancer: tackle the bad guys with poison

Pancreatic cancer is one of the most devastating diseases with very poor prognosis. Only a small proportion is curable by surgical resection, whilst standard chemotherapy for patients with advanced disease has only modest effect with substantial toxicity. Therefore, there is an urgent need for the development of novel therapeutic approaches to improve the patient outcome. Recently the viral therapy is emerging as a novel effective therapeutic approach for cancer with the potential to selectively treat both primary tumor and metastatic lesions. This review provides an overview of the current status of viral treatment for pancreatic cancer, both in the laboratories and in clinical settings.

An oncolytic adenovirus regulated by a radiation-inducible promoter selectively mediates hSulf-1 gene expression and mutually reinforces antitumor activity of I131-metuximab in hepatocellular carcinoma

Gene therapy and antibody approaches are crucial auxiliary strategies for hepatocellular carcinoma (HCC) treatment. Previously, we established a survivin promoter-regulated oncolytic adenovirus that has inhibitory effect on HCC growth. The human sulfatase-1 (hSulf-1) gene can suppress the growth factor signaling pathways, then inhibit the proliferation of cancer cells and enhance cellular sensitivity to radiotherapy and chemotherapy. I(131)-metuximab (I(131)-mab) is a monoclonal anti-HCC antibody that conjugated to I(131) and specifically recognizes the HAb18G/CD147 antigen on HCC cells. To integrate the oncolytic adenovirus-based gene therapy and the I(131)-mab-based radioimmunotherapy, this study combined the CArG element of early growth response-l (Egr-l) gene with the survivin promoter to construct a radiation-inducible enhanced promoter, which was used to recombine a radiation-inducible oncolytic adenovirus as hSulf-1 gene vector. When I(131)-mab was incorporated into the treatment regimen, not only could the antibody produce radioimmunotherapeutic effect, but the I(131) radiation was able to further boost adenoviral proliferation. We demonstrated that the CArG-enhanced survivin promoter markedly improved the proliferative activity of the oncolytic adenovirus in HCC cells, thereby augmenting hSulf-1 expression and inducing cancer cell apoptosis. This novel strategy that involved multiple, synergistic mechanisms, including oncolytic therapy, gene therapy and radioimmunotherapy, was demonstrated to exert an excellent anti-cancer outcome, which will be a promising approach in HCC treatment.