Tumor-specific promoter-driven adenoviral therapy for insulinoma

TSCRE: a comprehensive database for tumor-specific cis-regulatory elements

Cis-regulatory elements (CREs) and super cis-regulatory elements (SCREs) are non-coding DNA regions which influence the transcription of nearby genes and play critical roles in development. Dysregulated CRE and SCRE activities have been reported to alter the expression of oncogenes and tumor suppressors, thereby regulating cancer hallmarks. To address the strong need for a comprehensive catalogue of dysregulated CREs and SCREs in human cancers, we present TSCRE (http://tscre.zsqylab.com/), an open resource providing tumor-specific and cell type-specific CREs and SCREs derived from the re-analysis of publicly available histone modification profiles. Currently, TSCRE contains 1 864 941 dysregulated CREs and 68 253 dysregulated SCREs identified from 1366 human patient samples spanning 17 different cancer types and 9 histone marks. Over 95% of these elements have been validated in public resources. TSCRE offers comprehensive annotations for each element, including associated genes, expression patterns, clinical prognosis, somatic mutations, transcript factor binding sites, cancer-type specificity, and drug response. Additionally, TSCRE integrates pathway and transcript factor enrichment analyses for each study, enabling in-depth functional and mechanistic investigations. Furthermore, TSCRE provides an interactive interface for users to explore any CRE and SCRE of interest. We believe TSCRE will be a highly valuable platform for the community to discover candidate cancer biomarkers.

Bifidobacterium infantis-Mediated Herpes Simplex Virus-TK/Ganciclovir Treatment Inhibits Cancer Metastasis in Mouse Model

Previous studies have found that Bifidobacterium infantis-mediated herpes simplex virus-TK/ganciclovir (BF-TK/GCV) reduces the expression of VEGF and CD146, implying tumor metastasis inhibition. However, the mechanism by which BF-TK/GCV inhibits tumor metastasis is not fully studied. Here, we comprehensively identified and quantified protein expression profiling for the first time in gastric cancer (GC) cells MKN-45 upon BF-TK/GCV treatment using quantitative proteomics. A total of 159 and 72 differential expression proteins (DEPs) were significantly changed in the BF-TK/GCV/BF-TK and BF-TK/GCV/BF/GCV comparative analysis. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis enriched some metastasis-related pathways such as gap junction and cell adhesion molecules pathways. Moreover, the transwell assay proved that BF-TK/GCV inhibited the invasion and migration of tumor cells. Furthermore, immunohistochemistry (IHC) demonstrated that BF-TK/GCV reduced the expression of HIF-1α, mTOR, NF-κB1-p105, VCAM1, MMP13, CXCL12, ATG16, and CEBPB, which were associated with tumor metastasis. In summary, BF-TK/GCV inhibited tumor metastasis, which deepened and expanded the understanding of the antitumor mechanism of BF-TK/GCV.

Insulinoma-Associated Protein 1 (INSM1): Diagnostic, Prognostic, and Therapeutic Use in Small Cell Lung Cancer

Small cell lung carcinoma (SCLC) is an aggressive and difficult to treat cancer. Although immunohistochemistry is not mandatory for a SCLC diagnosis, it might be required, especially in small samples. Insulinoma-associated protein 1 (INSM1) is expressed in endocrine and nervous tissues during embryogenesis, generally absent in adults and re-expressed in SCLC and other neuroendocrine neoplasms. Its high specificity propelled its use as diagnostic biomarker and an attractive therapeutic target. Herein, we aim to provide a systematic and critical review on the use of INSM1 for diagnosis, prognostication and the treatment of SCLC. An extensive bibliographic search was conducted in PubMed® focusing on articles published since 2015. According to the literature, INSM1 is a highly sensitive (75–100%) and specific (82–100%) neuroendocrine immunohistochemical marker for SCLC diagnosis. It can be used in histological and cytological samples. Although advantageous, its standalone use is currently not recommended. Studies correlating INSM1 expression and prognosis have disclosed contrasting results, although the expression seemed to entail a worse survival. Targeting INSM1 effectively suppressed SCLC growth either as a suicide gene therapy regulator or as an indirect target of molecular-targeted therapy. INSM1 represents a valuable biomarker for a SCLC diagnosis that additionally offers vast opportunities for the development of new prognostic and therapeutic strategies.

Prognostic value and non-neuroendocrine role of INSM1 in small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) is a malignant lung neuroendocrine tumor with early metastasis, rapid progression, and poor outcomes. Insulinoma-associated protein 1 (INSM1) has been an excellent marker for neuroendocrine (NE) differentiation and widely used in the diagnosis of NE neoplasms, including SCLC. However, its role beyond NE diagnostic marker remained little reported.

METHODS

We examined immunohistochemical expression of INSM1 in 73 surgically resected SCLC, analyzed its prognostic value by Kaplan-Meier method, and investigated clinical-pathological features of INSM1 high SCLC. In vitro, We assessed INSM1 function on glucose intake, tumor migration, and Cisplatin resistance by 2-NBDG glucose uptake fluorescent assay, transwell assay, and ANNEXIN V/PI assay, respectively. In vivo, we evaluated the therapeutic value of metformin on reversing INSM1 induced chemoresistance by BALB/c nude mice xenograft tumor model.

RESULTS

High INSM1 expression was correlated with lymph node metastasis (LNM) (p = 0.0005), later TNM stages (p = 0.0003), and predicted poor survival (Log-rank p = 0.038). Multivariate Cox analysis confirmed INSM1 as an independent prognostic factor in SCLC (p = 0.012, HR:3.195, 95%CI:1.288-7.927). Interestingly, LNM was correlated with worse prognosis only in patients received chemotherapy (Log-rank p = 0.027) rather than the others (Log-rank p = 0.40). In patients having LNM and treated with chemotherapy, high INSM1 was correlated with worse clinic outcome (Log-rank p = 0.009). In vitro, overexpression of INSM1 decreased AMPK-α expression as well as glucose intake, promoted tumor cell migration, and limited the apoptosis induced by Cisplatin, which all could be reversed by Metformin. In vivo, INSM1 overexpression also contributed to tumor growth beyond inducing Cisplatin resistance.

CONCLUSION

Our finding suggested INSM1 played more role than a NE marker, partly through down-regulating AMPK signal. INSM1 may serve as a novel prognostic marker and therapeutic target in SCLC.

NIR-II Absorbing Semiconducting Polymer-Triggered Gene-Directed Enzyme Prodrug Therapy for Cancer Treatment

Exploration of facile strategies for precise regulation of target gene expression remains highly challenging in the development of gene therapies. Especially, a stimuli-responsive nanocarrier integrated with ability of noninvasive remote control for treating wide types of cancers is rarely developed. Herein, a NIR-II absorbing semiconducting polymer (PBDTQ) is employed to remotely activate the heat-inducible heat-shock protein 70 (HSP70) promoter under laser irradiation, further realizing regulation of gene-directed enzyme prodrug therapy (GDEPT) for cancer treatment in mild hyperthermia. In this multifunctional nanocomposite, the PBDTQ and double suicide gene plasmid (pSG) based on HSP70 promoter are incorporated into a lipid complex. Upon NIR-II laser excitation, the mild photothermal effect (≈43 °C) generated from PBDTQ can cause the release of pSG and activation of HSP70 promoter, and then upregulate suicide gene expression triggered by the HSP70 promoter which can further convert the nontoxic prodrug into its cytotoxic metabolites. Therefore, this work demonstrates a universal NIR-II laser-triggered GDEPT using semiconducting polymers as the photothermal generator for cancer treatment with minimized collateral damage and nontargeted side effects.

Efficacy of an Oncolytic Adenovirus Driven by a Chimeric Promoter and Armed with Decorin Against Renal Cell Carcinoma

Virus-targeted therapy for tumors can effectively prolong the survival rate of patients and has become a new trend for cancer biotherapy. Oncolytic adenovirus (OAd) can specifically replicate in tumor cells, allowing the therapeutic genes carried to be rapidly copied. As known, solid tumors are always hypoxic, and researchers often overlook a key point, the replication of OAd depends not only on its own activity but also on the cellular hypoxic environment in which the virus replicates. In this study, we constructed an OAd carrying Decorin, HRE-Ki67-Decorin, combining the Ki67 promoter upstreamed with hypoxia-response element (HRE) sequences to drive adenoviral E1A. The OAd HRE-Ki67-Decorin had better replication ability under hypoxic conditions, downregulated cellular immunosuppressed growth factor TGF-β. In addition, HRE-Ki67-Decorin was potent in suppressing tumor growth and participated in the assembly of tumor extracellular matrix by expressing Decorin in subcutaneous renal cancer cell tumor models. Tumor sections from HRE-Ki67-Decorin-treated tissues had less collagen fibers and more spread of virus among tumor tissues. These results indicated that chimeric HRE-Ki67 promoter-regulated OAd carrying Decorin might be an effective anticancer treatment strategy.

Insulinoma-associated protein 1 (INSM1): a potential biomarker and therapeutic target for neuroendocrine tumors

BACKGROUND

Insulinoma-associated protein 1 (INSM1), a transcriptional regulator with a zinc-finger DNA-binding domain, has been validated as a cytoplasmic marker for neuroendocrine differentiation of tumor cells. Next to its abundant expression in the fetal pancreas, it is expressed in brain tumors, pheochromocytomas, medullary thyroid carcinomas, insulinomas and pituitary and small-cell lung carcinomas. INSM1 is not expressed in normal adult tissues and/or most non-neuroendocrine tumors. It regulates various downstream signaling pathways, including the Sonic Hedgehog, PI3K/AKT, MEK/ERK1/2, ADK, p53, Wnt, histone acetylation, LSD1, cyclin D1, Ascl1 and N-Myc pathways. Although INSM1 appears to be a subtle and specific biomarker for neuroendocrine tumors, its role in tumor development has remained unclear.

CONCLUSIONS

Here, we highlight INSMI expression, as well as its diagnostic significance and use as a therapeutic target in various neuroendocrine tumors. Targeting signaling pathways or gene expression alterations associated with INSM1 expression may be instrumental for the design of novel therapeutic strategies for neuroendocrine tumors.

Insulinoma-Associated-1: From Neuroendocrine Tumor Marker to Cancer Therapeutics

Insulinoma-associated-1 (IA-1 or INSM1) encodes a zinc-finger transcription factor, which was isolated from a human insulinoma subtraction library, with specific expression patterns, predominantly in developing neuroendocrine tissues and tumors. INSM1 is key in early pancreatic endocrine, sympatho-adrenal lineage, and pan-neurogenic precursor development. Insm1 gene ablation results in impairment of pancreatic β cells, catecholamine biosynthesis, and basal progenitor development during mammalian neocortex maturation. Recently, INSM1 has emerged as a superior, sensitive, and specific biomarker for neuroendocrine tumors. INSM1 regulates downstream target genes and exhibits extranuclear activities associated with multiple signaling pathways, including Sonic Hedgehog, PI3K/AKT, MEK/ERK^1/2, ADK, p53, Wnt, histone acetylation, LSD1, cyclin D1, Ascl1, and N-myc. Novel strategies targeting INSM1-associated signaling pathways facilitate the suppression of neuroendocrine tumor growth. In addition, INSM1 promoter-driven reporter assay and/or suicide gene therapy are promising effective therapeutic approaches for targeted specific neuroendocrine tumor therapy. In this review, the current knowledge of the biological role of INSM1 as a neuroendocrine tumor biomarker is summarized, and novel strategies targeting multiple signaling pathways in the context of INSM1 expression in neuroendocrine tumors are further explored. IMPLICATIONS: Neuroendocrine transcription factor (INSM1) may serve as a neuroendocrine biomarker for the development of novel cancer therapeutics against neuroendocrine tumors.

A novel synthetic human insulin super promoter for targeting PDX-1-expressing pancreatic cancer

Our previous studies have shown that a rat insulin promoter II fragment (RIP) was used to effectively target pancreatic adenocarcinoma (PDAC) and insulinoma that over-express pancreatic and duodenal homeobox-1 (PDX-1). To enhance the activity and specificity of the human insulin promoter, we engineered a synthetic human insulin super-promoter (SHIP). Reporter assay demonstrated that SHIP1 was the most powerful promoter among all of the SHIPs and had far greater activity than the endogenous human insulin promoters and RIP in PDAC expressing PDX-1. Over-expression, knockdown and competitive inhibition of PDX-1 expression assay proved that PDX-1 is a critical transcript factor to regulate the activity of SHIP1. SHIP1-driven viral thymidine kinase followed by ganciclovir (SHIP1-TK/GCV) resulted in cytotoxicity to PDAC cells in vitro. Systemic delivery of SHIP1-TK/GCV in PDAC xenograft mice significantly suppressed PANC-1 tumor growth in vivo greater than RIP-TK/GCV and CMV-TK/GCV controls (p < .05). These preclinical data suggest that SHIP1 is a powerful novel promoter that can be used to target human PDAC expressing PDX-1 in clinical trials. Furthermore, this novel strategy of engineering synthetic super-promoters could be used for other cancer targets.

Oncolytic virus-induced cell death and immunity: a match made in heaven?

Our understanding of the mechanisms responsible for cancer development has increased enormously over the last decades. However, for many cancers, this has not been translated into a significant improvement in overall survival, and overall mortality remains high. Treatment for many malignancies remains based on surgery, chemotherapy, and radiotherapy. Significant progress has been made toward the development of more specific, more potent, and less invasive treatment modalities, but such targeted therapies remain the exception for most cancers. Thus, cancer therapies based on a different mechanism of action should be explored. The immune system plays an important role in keeping tumor growth at bay. However, in many cases, these responses are not strong enough to keep tumor growth under control. Thus, immunotherapy aims to boost the immune system to suppress tumor growth efficiently. This has been demonstrated by the recent successes of immune checkpoint therapy in several cancers. Oncolytic viruses (OVs) are another exciting class of immunotherapy agent. As well as replicating selectively within and killing tumor cells, OVs are able to elicit potent anti-tumor immune responses. Therapeutic vaccination with OVs, also referred to as cancer virotherapy, can thus be tailored to elicit vigorous cellular immune responses and even target individual malignancies in a personalized manner. In this review, we will describe the intricate link among oncolytic virotherapy, tumor immunology, and immunogenic cell death (ICD) and discuss ways to harness optimally their potential for future cancer therapy.

Oncolytic viruses-immunotherapeutics on the rise

The oncolytic virus (OV) field has entered an exciting period in its evolution in which our basic understanding of viral biology and anti-cancer potential are being actively translated into viable therapeutic options for aggressive malignancies. OVs are naturally occurring or engineered viruses that are able to exploit cancer-specific changes in cellular signaling to specifically target cancers and their microenvironment. The direct cytolytic effect of OVs on cancer cells is known to release antigens, which can begin a cascade of events that results in the induction of anti-cancer adaptive immunity. This response is now regarded as the most critical mechanism of OV action and harnessing it can lead to the elimination of distant micrometastases as well as provide long-term anti-cancer immune surveillance. In this review, we highlight the development of the OV field, why OVs are gaining an increasingly elevated standing as members of the cancer immunotherapy armamentarium, and finally, ongoing clinical studies that are aimed at translating unique OV therapies into approved therapies for aggressive cancers.