hTERT and BIRC5 gene promoters for cancer gene therapy: A comparative study

Construction of an Anoikis-Related Gene Prognostic Signature and Identification of ANGPTL4 as a Key Oncogene in Lung Adenocarcinoma

Anoikis plays an important role in cancer invasion and metastasis. However, the role of anoikis-related genes, AnRGs, in lung adenocarcinoma (LUAD) is not clear. First, anoikis-related genes (AnRGs) were obtained from the Genecard database. Second, the prognostic risk model of AnRGs was established by univariate Cox analysis, the Least Absolute Shrinkage and Selection Operator (LASSO) analysis, and multivariate Cox analysis. Finally, in vitro cell experiments were carried out to determine the expression and function of the key gene AnRGs. Three AnRGs (angiopoietin-like 4, ANGPTL4; Cyclin-Dependent Kinase Inhibitor 3, CDKN3; Solute Carrier Organic Anion Transporter Family Member 1B3, SLCO1B3) were screened for the construction of risk prediction model. Additionally, ANGPTL4 was significantly highly expressed in tumor cells, and the knockdown of ANGPTL4 expression on tumor cells could inhibit tumor cell migration and apoptosis. Constructing a risk model based on anoikis-related genes can effectively differentiate the prognosis of LUAD. ANGPTL4 can be used as a potential new target for LUAD treatment.

Tumor vessel co-option: The past & the future

Tumor vessel co-option (VCO) is a non-angiogenic vascularization mechanism that is a possible cause of resistance to anti-angiogenic therapy (AAT). Multiple tumors are hypothesized to primarily rely on growth factor signaling-induced sprouting angiogenesis, which is often inhibited during AAT. During VCO however, tumors invade healthy tissues by hijacking pre-existing blood vessels of the host organ to secure their blood and nutrient supply. Although VCO has been described in the context of AAT resistance, the molecular mechanisms underlying this process and the profile and characteristics of co-opted vascular cell types (endothelial cells (ECs) and pericytes) remain poorly understood, resulting in the lack of therapeutic strategies to inhibit VCO (and to overcome AAT resistance). In the past few years, novel next-generation technologies (such as single-cell RNA sequencing) have emerged and revolutionized the way of analyzing and understanding cancer biology. While most studies utilizing single-cell RNA sequencing with focus on cancer vascularization have centered around ECs during sprouting angiogenesis, we propose that this and other novel technologies can be used in future investigations to shed light on tumor EC biology during VCO. In this review, we summarize the molecular mechanisms driving VCO known to date and introduce the models used to study this phenomenon to date. We highlight VCO studies that recently emerged using sequencing approaches and propose how these and other novel state-of-the-art methods can be used in the future to further explore ECs and other cell types in the VCO process and to identify potential vulnerabilities in tumors relying on VCO. A better understanding of VCO by using novel approaches could provide new answers to the many open questions, and thus pave the way to develop new strategies to control and target tumor vascularization.

Association of Polymorphism in Survivin Gene and the Risk of Liver Cancer Resulting from Hepatitis C Virus Among Egyptian Patients

BACKGROUND

This study aims to investigate the relation between Survivin gene polymorphisms and the risk of Hepatocellular carcinoma (HCC) resulting from hepatitis C infection among the Egyptian population.

METHODS

This prospective study was conducted on 164 patients, 57 patients were diagnosed with hepatitis C, where 57 were diagnosed with HCC in addition to 50 healthy volunteers as controls. Genotyping for Survivin rs1042489 and rs8073069 single nucleotide polymorphisms was carried out by the allelic discrimination Real-Time Polymerase Chain Reaction Single Nucleotide Polymorphisms genotyping technology.

RESULTS

The results of Survivin rs1042489 polymorphism revealed that the TC and CC genotypes were significantly different between hepatocellular carcinoma patients (OR=15.5, 95%CI: 3.299-72.825,P<0.001), and controls (OR=44, 95%CI: 8.025-241.254, P<0.001). Furthermore, CC genotype was significantly different between cirrhotic and hepatocellular carcinoma patients (OR=19.2, 95%CI: 3.097-119.049, P=0.002). Moreover, the TC genotype shows a significant difference between controls and cirrhotic patients (OR=5.5, 95%CI: 2.111-14.328, P<0.001). However, when comparing TT genotypes, CC+TC genotypes results showed a significant association with increasing the risk of cirrhosis and hepatocellular carcinoma (OR=4.812, 95%CI: 1.893-12.233, P=0.001), (OR=21.607, 95%CI: 4.738-98.532, P<0.01), respectively. On the other hand, there was no significant difference among all studied groups for all genotypes regarding Survivin rs8073069. Also, the CC+GC genotype showed no significant association with increased risk of hepatocellular carcinoma (P=0.999) compared with the GG genotypes.

CONCLUSION

The study indicates that functional Survivin rs1042489 polymorphism may contribute to the risk of hepatocellular carcinoma while Survivin rs8073069 polymorphism has no significant association with increased risk of hepatocellular carcinoma among the studied groups.

Analysis of endogenous and exogenous tumor upregulated promoter expression in canine tumors

Gene therapy is a promising treatment option for cancer. However, its utility may be limited due to expression in off-target cells. Cancer-specific promoters such as telomerase reverse transcriptase (TERT), survivin, and chemokine receptor 4 (CXCR4) have enhanced activity in a variety of human and murine cancers, however, little has been published regarding these promoters in dogs. Given the utility of canine cancer models, the activity of these promoters along with adenoviral E2F enhanced E1a promoter (EEE) was evaluated in a variety of canine tumors, both from the endogenous gene and from exogenously administered constructs. Endogenous expression levels were measured for cTERT, cSurvivin, and cCXCR4 and were low for all three, with some non-malignant and some tumor cell lines and tissues expressing the gene. Expression levels from exogenously supplied promoters were measured by both the number of cells expressing the construct and the intensity of expression in individual cells. Exogenously supplied promoters were active in more cells in all tumor lines than in normal cells, with the EEE promoter being most active, followed by cTERT. The intensity of expression varied more with cell type than with specific promoters. Ultimately, no single promoter was identified that would result in reliable expression, regardless of the tumor type. Thus, these findings imply that identification of a pan-cancer promoter may be difficult. In addition, this data raises the concern that endogenous expression analysis may not accurately predict exogenous promoter activity.

Xenobiotic Response Elements (XREs) from Human CYP1A1 Gene Enhance the hTERT Promoter Activity

A hybrid 6XRE-hTERT promoter consisting of the hTERT tumor-specific promoter and six copies of the XRE element from the CYP1A1 human gene promoter was created. Using a human lung cancer cells as a model, we showed that XRE elements in the hybrid promoter greatly increase the activity of the hTERT promoter and ensure the reporter gene transcriptional activation in response to the treatment of the cells with the AhR ligand benzo(a)pyrene. However, similar effects were also observed in normal human bronchial epithelial cells HBEpC, which indicates the loss of the tumor-specific activity by the 6XRE-hTERT hybrid promoter. XRE elements can be used for nonspecific transcription enhancement but are unsuitable for the creation of tumor-specific promoters with enhanced activity.

Significance of Serum Survivin and -31G/C Gene Polymorphism in the Early Diagnosis of Breast Cancer in Egypt

BACKGROUND

Breast cancer is one of the most relevant malignancies among women. Molecular abnormalities in promotor region of survivin gene may account for overexpression of survivin and increased breast cancer risk. This study aimed to explore the potential association between survivin promotor gene -31G/C single nucleotide polymorphism (rs9904341) and its serum level alteration on one hand, and the risk of breast cancer in Egyptian patients on the other hand. It also aimed to assess the usefulness of survivin as an early noninvasive diagnostic biomarker and in breast cancer staging.

PATIENTS AND METHODS

A total of 135 patients with physically and pathologically confirmed breast cancer and 40 unrelated control subjects as well as 40 patients with benign breast mass were recruited from the early detection unit at National Cancer Institute, Cairo University. Genotyping was performed using allelic discrimination probes by real-time quantitative PCR and serum survivin by enzyme-linked immunosorbent assay.

RESULTS

The minor allele C of -31G/C survivin single nucleotide polymorphism was more frequent in breast cancer patients (19.3%) compared to the control group (7.5%). Furthermore, subjects with the GC + CC genotype were at increased risk of breast cancer compared to the GG genotype of the control group and also the benign group. Moreover, those patients exhibited higher serum levels of survivin compared to GG genotype. There was also significant elevation of serum survivin in different breast cancer stages.

CONCLUSION

Genetic variation in -31G/C of the survivin gene may contribute to the disposition of breast cancer in the Egyptian population. Serum survivin alteration played a pivotal role in the pathogenesis of breast cancer.

MiR-3613-3p affects cell proliferation and cell cycle in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors with poor sensitivity to chemotherapy drugs and poor prognosis among patients. In the present study, we downloaded the original data from the Gene Expression Omnibus and compared gene expression profiles of liver cancer cells in patients with HCC with those of colon epithelial cells of healthy controls to identify differentially expressed genes (DEGs). After filtering target microRNAs (miRNA) from core DEGs, we cultured HepG2 cells in vitro, knocked down the miRNA and core mRNAs, and analyzed the effects. We found 228 differentially expressed genes between liver cancer tissue and healthy control tissue. We also integrated the protein-proteininteraction network and module analysis to screen 13 core genes, consisting of 12 up-regulated genes and 1 down-regulated gene. Five core genes were regulated hsa-miR-3613-3p, therefor we hypothesized that hsa-miR-3613-3p was a critical miRNA. After the transfection procedure, we found that changes in hsa-miR-3613-3p were the most obvious. Therefore, we speculated that hsa-miR-3613-3p was a main target miRNA. In addition, we transfected with si (BIRC5, CDK1, NUF2, ZWINT and SPC24), to target genes that can be targeted by miR-3613-3p. Our data shows that BIRC5, NUF2, and SPC24 may be promising liver cancer biomarkers that may not only predict disease occurrence but also potential personalized treatment options.

Multidimensional integrative analysis uncovers driver candidates and biomarkers in penile carcinoma

Molecular data generation and their combination in penile carcinomas (PeCa), a significant public health problem in poor and underdeveloped countries, remain virtually unexplored. An integrativemethodology combin ing genome-wide copy number alteration, DNA methylation, miRNA and mRNA expression analysis was performed in a set of 20 usual PeCa. The well-ranked 16 driver candidates harboring genomic alterations and regulated by a set of miRNAs, including hsa-miR-31, hsa-miR-34a and hsa-miR-130b, were significantly associated with over-represented pathways in cancer, such as immune-inflammatory system, apoptosis and cell cycle. Modules of co-expressed genes generated from expression matrix were associated with driver candidates and classified according to the over-representation of passengers, thus suggesting an alteration of the pathway dynamics during the carcinogenesis. This association resulted in 10 top driver candidates (AR, BIRC5, DNMT3B, ERBB4, FGFR1, PML, PPARG, RB1, TNFSF10 and STAT1) selected and confirmed as altered in an independent set of 33 PeCa samples. In addition to the potential driver genes herein described, shorter overall survival was associated with BIRC5 and DNMT3B overexpression (log-rank test, P = 0.026 and P = 0.002, respectively) highlighting its potential as novel prognostic marker for penile cancer.

Targeted CDX2 expression inhibits aggressive phenotypes of colon cancer cells in vitro and in vivo

Loss of caudal type homeobox 2 (CDX2) is associated with the development of human colorectal cancer, while human telomerase reverse transcriptase (hTERT) frequently occurs in variety of human cancers. We investigated the effects of restoration of CDX2 expression using a hypoxia-inducible hTERT promoter-driven vector (pLVX-5HRE-hTERTp-CDX2-3FLAG) on colon cancer cell viability, cell cycle distribution, apoptosis, colony formation, invasion ability and xenograft tumor growth in nude mice. CDX2 overexpression significantly inhibited viability, colony formation, and the invasion and migration ability of LoVo cells, and induced cell cycle arrest and apoptosis in vitro, especially under hypoxic culture conditions. Overexpression of CDX2 under normoxic conditions significantly suppressed the expression of TGF-β, cyclin D1, uPA, MMP-9, MMP-2, and Bcl-2, and stimulated the expression of collagen IV, laminin-1, and Bax. Overexpression of CDX2 reduced colon cancer xenograft tumor formation in nude mice which was associated with downregulation of Ki-67. In conclusion, overexpression of CDX2 using a hypoxia-inducible hTERT promoter-driven vector suppressed malignant progression of colon cancer cells in vitro and in vivo. These results suggest that pLVX-5HRE-hTERTp-CDX2-3FLAG gene therapy may be a promising novel approach to treat colon cancer.

A Novel Hybrid Promoter ARE-hTERT for Cancer Gene Therapy

describe a novel hybrid tumor-specific promoter, ARE-hTERT, composed of the human TERT gene promoter (hTERT) and the antioxidant response element (ARE) from the human GCLM gene promoter. The hybrid promoter retains the tumor specificity of the basal hTERT promoter but is characterized by an enhanced transcriptional activity in cancer cells with abnormal activation of the Nrf2 transcription factor and upon induction of oxidative stress. In the in vitro enzyme-prodrug cancer gene therapy scheme, ARE-hTERT promoter-driven expression of CD : UPRT (yeast cytosine deaminase : uracil phosphoribosyltransferase) chimeric protein induced a more pronounced death of cancer cells either upon treatment with 5-fluorouracil (5FC) alone or when 5FC was combined with chemotherapeutic drugs as compared to the hTERT promoter. The developed hybrid promoter can be considered a better alternative to the hTERT promoter in cancer gene therapy schemes.