Comparative efficacy and safety of weekly dulaglutide versus weekly insulin in type 2 diabetes: A network meta-analysis of randomized clinical trials

Background

Advancements in type 2 diabetes mellitus (T2DM) therapy, notably with weekly agents like glucagon-like peptide-1 receptor agonists (GLP-RAs) such as dulaglutide, offer promising outcomes in clinical practice. The emergence of once-weekly insulin adds to this therapeutic arsenal. This research aims to explore and compare the efficacy and safety profiles of these agents in diabetes management, facilitating informed decision-making for optimizing their utilization in clinical practice.

Methods

A systematic search of PubMed, Scopus, Cochrane, and Web of Science databases was conducted. The research protocol was registered at OSF registries (https://osf.io/gd67x). The primary outcome of interest was the change in hemoglobin A1C (HbA1c), with secondary outcomes including the change in fasting plasma glucose, body weight, prevalence of hypoglycemia, and treatment discontinuation due to adverse events. The evaluation of bias risk was conducted utilizing the RoB2 tool developed by the Cochrane Collaboration. Statistical analysis was performed using RStudio version 4.3.2 with the meta package version 7.0-0 and the netmeta package version 2.9-0. Confidence in network meta-analysis estimates was evaluated using the CINeMA (Confidence In Network Meta-Analysis). Heterogeneity was assessed by comparing the magnitude of the common between-study variance (τ2) for each outcome with empirical distributions of heterogeneity variances.

Results

Dulaglutide 1.5 mg (mg) weekly demonstrated superior reduction in hemoglobin A1C (HbA1c) compared to insulin, with a mean difference (MD) of -0.35 (95 % CI: -0.51 to -0.19). Additionally, Dulaglutide 1.5 mg exhibited greater weight loss, with an MD of -3.12 (95 % CI: -3.55 to -2.68). However, it also showed a higher rate of adverse events, with an odds ratio (OR) of 1.40 (95 % CI: 1.12 to 1.75) compared to insulin. Both doses of Dulaglutide (1.5 mg and 0.75 mg) had lower prevalence of hypoglycemia compared to insulin, with ORs of 0.60 (95 % CI: 0.41 to 0.87) and 0.59 (95 % CI: 0.41 to 0.86), respectively. There was no significant difference in treatment discontinuation among the treatment groups.

Conclusion

Dulaglutide, particularly at higher doses, demonstrates superior efficacy in lowering hemoglobin A1C and reducing hypoglycemia risk compared to Icodec insulin in type 2 diabetes management. However, its use is also associated with a higher incidence of adverse events. Clinicians should carefully consider these factors when selecting optimal treatment strategies for patients with type 2 diabetes mellitus.

Association of NOS3 Genetic Polymorphism With the Predisposition to Diabetes and Pre-Diabetes, Retrospective Study

Background: Endothelial nitric oxide synthetase (eNOS) encoded by NOS3 gene has an important role in modulating vascular endothelial function. Many studies reported a possible role of NOS3 in the pathogenesis of diabetes mellitus (DM). This study investigated the association of NOS3 (G>T) rs1799983 genetic polymorphism with DM, pre-diabetes (pre-DM), and insulin resistance (IR).

Methods: A random sample of 220 subjects (DM & pre-DM) compared with 220 healthy subjects. Sample obtained from Palestinian adults who consented to genetic and biochemical testing. All subjects genotyped for NOS3 (G > T) rs1799983 SNP using ARMS PCR. Fasting blood sugar (FBS) and triglyceride (TGA) levels were obtained for all subjects. Triglyceride glucose index (TyG) was used as a surrogate marker for IR. Regression analysis adjusted for age and body mass index (BMI) was performed to investigate the association between DM & Pre-DM status, FBS, and TyG with NOS3 genetic polymorphism.

Results: NOS3 minor allele frequency positively correlated with FBS levels after controlling for age and BMI (P-value 0.006). DM & pre-DM were more frequent in homozygous NOS3 subjects with an odds ratio of 2.04 (P = 0.05). NOS3 minor allele frequency positively correlated with TyG but not statistically significant association (P = 0.061).

Discussion: Many studies reported a potential role of NOS3 genetic polymorphism in DM and IR pathogenesis. In this study, NOS3 minor allele frequency positivity correlated with FBS levels. Homozygous NOS3 was associated with a 2-fold increase in the prevalence of DM & pre-DM. NOS3 genetic polymorphism didn’t show a statistically significant correlation with TyG (P = 0.061). With the increasing availability of genetic testing, NOS3 may serve as an early screening tool to identify subjects with a high risk for elevated FBS. Further studies are required to understand the exact role of NOS3 genetic polymorphism in the pathogenesis of DM, and to evaluate the clinical efficacy and cost-effectiveness of genetic testing.

Conclusion: NOS3 genetic polymorphism has a statistically significant relationship with the FBS level. Further studies are required to confirm the association between NOS3 and DM.

Association of NOS3 and TNF Genetic Polymorphisms With the Predisposition to Elevated Cholesterol, Retrospective Study

Background: Endothelial nitric oxide synthetase (eNOS) encoded by NOS3 gene has an important role in modulating vascular endothelial function. TNFα gene is responsible for coding TNFα protein that plays a significant role in regulating body inflammation and lipid metabolism. Many studies reported an association between NOS3 and TNFα genetic polymorphisms and elevated total cholesterol (TC) level, low-density lipoprotein (LDL), triglyceride (TG). In this study, we investigated the association of NOS3 (G>T) rs1799983 and TNFα -308G>A rs1800629 genetic polymorphisms with TC level.

Methods: A random sample of 250 subjects with an elevated TC level (defined by TC level ≥ 200mg/dL) compared with 500 healthy subjects. Sample obtained from Palestinian adults who consented to genetic and biochemical testing. Subjects genotyped for NOS3 SNP (G > T) rs1799983 and TNFα -308G>A rs1800629 using ARMS PCR. TC level was obtained for all subjects. Logistic regression analysis adjusted for age and body mass index (BMI) was performed to test for association between NOS3 and TNFα genetic polymorphisms and TC level.

Results: NOS3 T allele was significantly more frequent in the elevated TC group, (odds ratio = 1.8, 95% CI =1.02–3.18) with likelihood ratio statistically significant (P = 0.004). Homozygous TNFα variant was more frequent in the elevated cholesterol group without a statistically significant association (P = 0.54).

Discussion: Many studies reported an association between NOS3 and TNFα genetic polymorphisms and elevated TC levels. Homozygous NOS3 variant was associated with a 1.8-fold increase in the risk of high TC after adjustment for age and BMI. TNFα polymorphism didn’t show a statistically

significant association with having elevated TC levels. With the increasing popularity and availability of genetic testing, NOS3 can serve as a screening tool to identify people with high risk for elevated TC. Further studies are required to understand the exact role of NOS3 genetic polymorphism in cholesterol metabolism.

Conclusion: NOS3 genetic polymorphism had a statistically significant relationship with TC levels. These results support the association between NOS3 polymorphism and elevated TC.

Unraveling the genetic cause of hereditary ophthalmic disorders in Arab societies from Israel and the Palestinian Authority

Visual impairment due to inherited ophthalmic disorders is amongst the most common disabilities observed in populations practicing consanguineous marriages. Here we investigated the molecular genetic basis of an unselected broad range of ophthalmic disorders in 20 consanguineous families from Arab villages of Israel and the Palestinian Authority. Most patients had little or very poor prior clinical workup and were recruited in a field study. Homozygosity mapping followed by candidate gene sequencing applying conventional Sanger sequencing or targeted next generation sequencing was performed in six families. In the remaining 14 families, one affected subject per family was chosen for whole exome sequencing. We discovered likely disease-causing variants, all homozygous, in 19 of 20 independent families (95%) including a previously reported novel disease gene for congenital nystagmus associated with foveal hypoplasia. Moreover, we found a family in which disease-causing variants for two collagenopathies - Stickler and Knobloch syndrome - segregate within a large sibship. Nine of the 19 distinct variants observed in this study were novel. Our study demonstrated a very high molecular diagnostic yield for a highly diverse spectrum of rare ophthalmic disorders in Arab patients from Israel and the Palestinian Authority, even with very limited prior clinical investigation. We conclude that 'genetic testing first' may be an economic way to direct clinical care and to support proper genetic counseling and risk assessment in these families.

MEGDEL Syndrome in a Child From Palestine: Report of a Novel Mutation in SERAC1 Gene

We report the first Palestinian child manifesting with 3-methylglutaconic aciduria psychomotor delay, muscle hypotonia, sensori-neural deafness, and Leigh-like lesions on brain magnetic resonance imaging (MRI), a clinical phenotype that is characteristic of MEGDEL syndrome. MEGDEL syndrome was recently found to be caused by mutations in SERAC1, encoding a protein essential for mitochondrial function, phospholipid remodeling, and intracellular cholesterol trafficking. We identified a novel homozygous mutation in SERAC1 gene (c.1018delT) that generates frame shift and premature termination of protein translation. Plasma and cerebrospinal fluid lactate, plasma alanine, and respiratory chain complexes in fresh muscle were normal. This report further expands the genetic spectrum of MEGDEL syndrome and adds to the evidence that it is associated with variable patterns of respiratory chain abnormalities.

ABCB1 C3435T and CYP2C19*2 polymorphisms in a Palestinian and Turkish population: A pharmacogenetic perspective to clopidogrel

Clopidogrel is an antiplatelet drug used to prevent recurrent ischemic events after acute coronary syndrome and/or coronary stent implantation. Single nucleotide polymorphisms (SNPs) such as CYP2C19*2 and ABCB1 C3435T have been found to play a role in different individual responses to clopidogrel. Since the prevalence of these SNPs is generally known to differ from one population to another, the aim of this study was to examine their prevalence in both a Palestinian and Turkish population. One hundred unrelated Palestinian subjects and 100 unrelated Turkish subjects were analyzed for CYP2C19*2 and ABCB1 C3435T polymorphisms by the amplification refractory mutation system (ARMS). Results showed an ABCB1 3435 T allele frequency of 0.46 (95% CI 0.391 to 0.529) in the Palestinian sample and 0.535 (95% CI 0.4664 to 0.6036) in the Turkish sample. CYP2C19*2 allele frequency was 0.095 (95% CI 0.0558 to 0.134) in the Palestinian sample and 0.135 (95% CI 0.088 to 0.182) in the Turkish sample. Our results provide information about the prevalence of the polymorphisms related to clopidogrel response in both the Palestinian and Turkish populations, in order to improve the safety and efficacy of clopidogrel through use of genetically guided, individualized treatment. The prevalence of these clinically significant alleles shed light on the importance of testing them before prescribing clopidogrel.

beta(S)-Globin gene cluster haplotypes in the West Bank of Palestine

Sickle cell disease is an inherited autosomal recessive disorder of the beta-globin chain. In Palestine it is accompanied by a low level of Hb F (mean 5.14%) and a severe clinical presentation. In this study, 59 Palestinian patients, homozygotes for Hb S were studied for their haplotype background. Eight polymorphic sites in the beta-globin gene cluster were examined. The Benin haplotype was predominant with a frequency of 88.1%, followed by a frequency of 5.1% for the Bantu haplotype. One chromosome was found to carry the Cameroon haplotype (0.85%). Three atypical haplotypes were also found (5.95%). Heterogeneity was observed in Hb F production, ranging between 1.5 and 17.0%, whereas the (G)gamma ratio was homogeneous among all haplotypes with a normal amount of about 41%. Our results are in agreement with previous reports of the Benin haplotype origin in the Mediterranean.

The H19 non-coding RNA is essential for human tumor growth

Background

Mutations and epigenetic aberrant signaling of growth factors pathways contribute to carcinogenesis. Recent studies reveal that non-coding RNAs are controllers of gene expression. H19 is an imprinted gene that demonstrates maternal monoallelic expression without a protein product; although its expression is shut off in most tissues postnatally, it is re-activated during adult tissue regeneration and tumorigenesis. Moreover, H19 is highly expressed in liver metastasis derived from a range of carcinomas. The objective of this study is to explore the role of H19 in carcinogenesis, and to determine its identification as an anti-tumor target.

Methodology/ Principle Findings

By controlling oxygen pressure during tumor cell growth and H19 expression levels, we investigated the role of H19 expression in vitro and in vivo in hepatocellular (HCC) and bladder carcinoma. Hypoxia upregulates the level of H19 RNA. Ablations of tumorigenicity of HCC and bladder carcinomas in vivo are seen by H19 knockdown which also significantly abrogates anchorage-independent growth after hypoxia recovery, while ectopic H19 expression enhances tumorigenic potential of carcinoma cells in vivo. Knocking-down H19 message in hypoxic stress severely diminishes p57^kip2 induction. We identified a number of potential downstream targets of H19 RNA, including angiogenin and FGF18.

Conclusions

H19 RNA harbors pro-tumorigenic properties, thus the H19 gene behaves as an oncogene and may serve as a potential new target for anti-tumor therapy.

Differential Expression of Kinase Genes in Primary Hyperparathyroidism: Adenoma Versus Normal and Hyperplastic Parathyroid Tissue

Context.—Differentiation between adenoma and hyperplasia or even normal parathyroid tissue is difficult and based mainly on the surgeon's skill. Exploration of genes that express differentially in these various tissues using microarrays and other sophisticated research tools will enable identification and perhaps development of new methods of perioperative diagnosis.

Objective.—To assemble a panel of kinase genes to differentiate parathyroid adenoma from normal and hyperplastic parathyroid tissue.

Design.—RNA was extracted from adenoma, hyperplasia, and normal parathyroid tissue and hybridized to a microarray containing 359 human cDNAs of known kinase genes. Signals of exposure were scanned and quantified with software for digital image analysis. Semiquantitative reverse transcriptase polymerase chain reaction analysis of sample genes was performed, up-regulated or down-regulated, to validate the microarray results.

Results.—The ratio values considered significant (<0.5 or >1.5) suggest that genes up-regulated in parathyroid adenoma are those responsible for blood vessel angiogenesis and genes belonging to the cyclin-dependent kinase inhibitor groups. Genes down-regulated in parathyroid adenoma are related to cellular growth and apoptosis—genes from the mitogen-activated protein kinase group and DNA-dependent protein kinase group. An interesting gene down-regulated in the parathyroid adenoma samples is related to the serine/threonine protein kinases that exert a key function in calcium handling. A panel of 5 genes was defined: p19, p21 and the gene for vascular endothelial growth factor from the up-regulated group, and the gene for protein kinase C and SGK from the down-regulated group. Reverse transcriptase polymerase chain reaction confirmed the microarray results for these genes.

Conclusions.—The kinase genes panel presented can be used to differentiate parathyroid adenoma from normal and hyperplastic parathyroid tissue in particular when histopathology fails to provide a decisive diagnosis.

Chemically induced bladder cancer--a sonographic and morphologic description

OBJECTIVES

Carcinogen-induced bladder cancer in rodents is a key model for evaluation of novel therapies for bladder cancer because of its similarity to the clinical disease. The major drawback of the model is the difficulty in assessing tumor burden in living animals and at necropsy. The objective of this work was to present simple and accurate solutions for this problem.

METHODS

Sixty female Wistar rats were given N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) at a concentration of 0.05% in the drinking water for 35 weeks. Periodic evaluation of tumorigenesis was done by ultrasonography of the anesthetized animals. The tumor burden was evaluated after killing the rats by weighing the bladder, digital measurement of the tumor dimensions, and histologic examination.

RESULTS

Focal urothelial hyperplasia was noted by the 5th BBN week, severe dysplasia by the 15th BBN week, and transitional cell carcinoma from the 20th week on. Carcinoma was seen on digital photographs taken from the 20th week on. Tumors as small as 1 mm could be easily measured. A poor correlation (R2 = 0.33) was found between bladder weight and the digital photographic measurements of small tumors (20th BBN week). However, when larger tumors were considered (30th BBN week), a good correlation was found (R2 = 0.81).

CONCLUSIONS

Tumor progress in the rat BBN model was accurately monitored by ultrasonography in living animals. Digital measurement of tumor dimensions provided a precise method for evaluation of tumor burden at necropsy.

A non-invasive QPCR method monitoring DNA based therapy of bladder cancer patients

Real-time PCR technology is highly advantageous for gene studies based on the genetic nature of the transferred material. Urine and blood samples were collected before and after treatment. Treatment of bladder carcinoma patients with plasmid constructs expressing the diphtheria toxin gene was monitored. Detection range from 5x10(6) copies to <or=10 copies was observed with repeatability and reproducibility. No trace amount of the plasmid was detected in the patient's bloodstream, and a continuous clearance in urine, as well, was observed 72 h post-injection. These results show the possibility to design a follow-up method to monitor quantitatively the amount of the plasmid DNA in bladder cancer patients.

Regulatory sequences of H19 and IGF2 genes in DNA-based therapy of colorectal rat liver metastases

BACKGROUND

Malignant tumors of the liver are among the most common causes of cancer-related death throughout the world. Current therapeutic approaches fail to control the disease in most cases. This study seeks to explore the potential utility of transcriptional regulatory sequences of the H19 and insulin growth factor 2 (IGF2) genes for directing tumor-selective expression of a toxin gene (A fragment of diphtheria toxin), delivered by non-viral vectors.

METHODS

The therapeutic potential of the toxin vectors driven by the H19 and the IGF2-P3 regulatory sequences was tested in a metastatic model of rat CC531 colon carcinoma in liver.

RESULTS

Intratumoral injection of these vectors into colon tumors implanted in the liver of rats induced an 88% and a 50% decrease respectively in the median tumor volume as compared with the control groups. This therapeutic action was accompanied by increased necrosis of the tumor. Importantly, no signs of toxicity were detected in healthy animals after their treatment by the toxin expression vectors.

CONCLUSIONS

DT-A was preferentially expressed in liver metastases after being transfected with H19 or IGF2-P3 promoter-driven DT-A expression plasmids, causing a very significant inhibition of tumor growth as a result of its cytotoxic effect. Our findings strongly support the feasibility of our proposed therapeutic strategy, which may contribute to open new gene therapeutic options for human liver metastases.

H19 expression in hepatic metastases from a range of human carcinomas

AIMS

To investigate the expression of the imprinted oncofetal H19 gene in hepatic metastases derived from a range of human carcinomas and assess its prognostic value with the view of developing a DNA based treatment for such metastases.

METHODS

Non-radioactive in situ hybridisation for H19 RNA was performed on paraffin wax embedded sections of liver biopsies or partial hepatectomy specimens, taken from 80 patients with hepatic metastases derived from carcinomas from several medical centres in Israel. The degree of expression was graded qualitatively according to the number of cells expressing H19 and the intensity of staining. The medical files were searched for demographic data and survival times before and after diagnosis of hepatic metastases.

RESULTS

H19 expression was found in the hepatic metastases of 64 of 80 patients. High expression (higher staining grades) of H19 in the metastases was found in 43 of 80 patients. However, H19 expression status in the hepatic metastases did not correlate with either the length of time to development of metastasis or overall survival.

CONCLUSIONS

H19 is highly expressed in more than half of hepatic metastases derived from a range of carcinomas. Thus, these metastases may be suitable candidates for H19 DNA based treatment. Further studies are needed to determine whether H19 expression has prognostic value in metastatic liver disease using larger numbers of specific subtypes of primary carcinomas.

Growth factor receptor-protein bound 2 (GRB2) upregulation in the placenta in preeclampsia implies a possible role for ras signalling

OBJECTIVES

To screen for genes with altered expression in placentas from pregnancies complicated by preeclampsia.

STUDY DESIGN

To corroborate gene expression profile of preeclamptic and normal placentas (ATLAS Clontech), by dot blot, Northern blot analysis and RT-PCR for growth factor receptor bound-protein 2 (GRB2), using immunohistochemistry to localize its expression in the placenta.

RESULTS

Increased expression of GRB2 upregulated in the microarrays was found in preeclampsia by Dot blot and Northern blot analysis. RT-PCR performed with primers specific for GRB2 and its alternatively spliced isoform GRB3-3 showed that most of the cDNA represented in the array was GRB2. The protein was localized to the smooth muscle wall of stem vessels by immunohistochemistry.

CONCLUSION

The ras signalling activated by placental receptor tyrosine kinases may play a role in the segmental thickening of the stem vascular wall in preeclamptic placentas, resulting in reduced blood flow to the developing fetus.

Spectrum of beta-globin gene mutations among thalassemia patients in the West Bank region of Palestine

beta-Thalassemia (thal) is an autosomal recessive disorder that results in hypochromic hemolytic anemia in affected patients. In the West Bank area of Palestine, the prevalence of beta-thal trait is approximately 3.5% among the population, with an estimated 120,000 carriers. Seventeen beta-globin gene mutations could be identified in 148 patients using polymerase chain reaction (PCR), amplification refractory mutation system (ARMS)-PCR and direct sequencing. The predominant mutations included: IVS-I-6 (T --> C) (28.7%), IVS-I-110 (G --> A) (17.6%), codon 37 (G --> A) (10.4%), IVS-I-1 (G --> A) (9%), codons 106/107 (+ G) (6.8%) and codon 39 (C --> T) (4.6%). Other less frequent and rare mutations included: IVS-II-1 (G --> A), codon 5 (-CT), IVS-II-848 (C --> A), -30 (T --> A), codons 8/9 (+ G), IVS-I-5 (G --> C), -28 (A --> C), IVS-II-745 (C --> G), codon 6(-A), codon 27 (G --> T) and codon 30 (AGG --> ACG). Most patients (62.2%) were homozygous for one type of mutation, while the rest (27.3%) were compound heterozygotes. Some patients were heterozygous for beta-thal and sickle cell anemia traits. No mutations could be detected in both alleles of eight patients, while in seven patients only one mutant allele could be detected. Further investigations are needed to resolve the corresponding genotypes of these patients. This study represents a comprehensive investigation of the type, frequency, and distribution of thalassemia mutations among the Palestinian population in the West Bank region of Palestine. A degree of similarity and significant variations was evident in the type and frequency of mutations when the present mutations profile was compared with similar ones among various Arab and non Arab populations. The association between the identified mutations and the corresponding genotypes of our patients with specific polymorphism frameworks in the beta-globin gene was performed and the results revealed linkage disequilibrium.

Gene expression in the bladder carcinoma rat model

We investigated gene expression in N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced rat bladder carcinoma in order to test its applicability as a model for the study of novel therapeutic modalities, particularly gene therapy. We administered BBN in the drinking water to Wistar rats for up to 30 wk and induced papillary transitional cell carcinoma (TCC), which is similar to the most prevalent type of human bladder cancer. Tumor evolution was similar to that found in previous studies. However, we described the morphological stages according to modern human bladder carcinoma terminology. Our main goal was to examine the expression levels of the H19 gene, of the insulin-like growth factor 2 (Igf2) transcripts expressed from promoters P2 and P3 and of the telomerase subunits that we had previously investigated as tools for targeted gene therapy of bladder cancer. We detected at 30 wk of BBN exposure significant upregulation of these sequences in the rat bladder tumors, similar to our previous findings in human bladder cancer. To reinforce the similarity of this model to the corresponding human disease, we searched for additional tumor-specific genes documented as having altered expression in human bladder carcinoma, using cDNA expression arrays (Clontech). We suggest that BBN-induced rat bladder cancer has morphological, biological, and molecular parallels to human bladder cancer and is an attractive model for studying novel alternatives of therapeutic intervention.

Oncofetal splice-pattern of the human H19 gene

H19 is an imprinted gene that demonstrates maternal monoallelic expression in fetal tissues and in some cancers, and very likely does not code for a protein. H19 is involved in the regulation of cell proliferation, embryonic growth, and differentiation through upstream and downstream cis elements that influence the expression of IGF2, a closely physically linked gene, and also through its RNA involved in metastasis and angiogenic processes. We report the identification of an alternatively spliced variant of H19 RNA that lacks part of exon 1. This variant was detected in human embryonic and placental tissues, but not in bladder or hepatocellular carcinomas. A very low level of this variant was also detected in colon carcinoma. The observed pattern of expression suggests that this splice variant is a developmentally regulated H19 gene transcript.

Inhibition of tumor growth by DT-A expressed under the control of IGF2 P3 and P4 promoter sequences

The human IGF2 P3 and P4 promoters are highly active in a variety of human cancers. We here present an approach for patient oriented therapy of TCC bladder carcinoma by driving the diphtheria toxin A-chain (DT-A) expression under the control of the IGF2 P3 and P4 promoter regulatory sequences. High levels of IGF2 mRNA expression from P3, P4 or both promoters were detected in 18 TCC samples (n = 29) by ISH or RT-PCR. Normal bladder samples (n = 4) showed no expression from either promoter. The activity and specificity of the IGF2 P3 and P4 regulatory sequences were established in human carcinoma cell lines by means of luciferase reporter gene assay. These sequences were used to design DT-A expressing, therapeutic vectors (P3-DT-A and P4-DT-A). The activity of both was determined in cell lines (in vitro) and the activity of P3-DT-A was determined in a heterotopic animal model (in vivo). The treated cell lines highly responded to the treatment in a dose-response manner, and the growth rate of the developed tumors in vivo was highly inhibited (70%) after intratumoraly injection with P3-DT-A compared to non-treated tumors (P < 0.0002) or tumors treated by luciferase gene expressing LucP3 vector (P < 0.002).

Expression of kinase genes in primary hyperparathyroidism: adenoma versus hyperplastic parathyroid tissue

BACKGROUND

Differentiation between parathyroid hyperplasia and adenoma is difficult and based on the surgeon's skill. Microarrays and other sophisticated research tools generate information about differential gene expression in various tissues. Exploration of genes that express differentially in 1 tissue will enable identification and perhaps development of new methods of preoperative or intraoperative diagnosis.

METHODS

RNA was extracted from parathyroid hyperplasia and adenoma tissue and hybridized to a microarray containing 359 human complementary DNAs of known kinase genes. Signals of exposure were scanned and quantified with software for digital image analysis (Atlas-image, v. 2; Clontech Labs Inc, Palo Alto, Calif). The program generates a color schematic comparison view and numeric data in a tabular format for further analysis.

RESULTS

The ratio values that are considered significant (< 0.5 or > 1.5) suggest that genes up-regulated in parathyroid adenoma are those responsible for angiogenesis and production of blood vessels. Genes down-regulated in parathyroid adenoma and expressed in hyperplasia are related to a decrease in apoptosis. Moreover, an interesting gene expressed only in the hyperplasia sample is increased in relation to in vivo proliferation activities.

CONCLUSIONS

Parathyroid hyperplasia and adenoma are different physiologic conditions. Further analysis of kinase genes involved in angiogenesis and apoptosis will enable design of a chip that concentrates in the different key genes responsible for the transition between hyperplasia and adenoma. Identifying such genes will enable to target both diagnostic and therapeutic approaches.

Possible physiological role of H19 RNA

The product of the imprinted oncofetal H19 gene is an untranslated RNA of unknown function. With the human cDNA Atlas microarray, we detected differentially expressed genes modulated by the presence of H19 RNA. Many of the genes that are upregulated by H19 RNA are known to contribute to the invasive, migratory, and angiogenic capacities of cells. Moreover, we provided experimental data indicating that whereas H19 RNA did not have any growth advantage for the cells when cultured in 10% fetal calf serum, it did confer an advantage when cells were cultured in serum-poor medium. This observation can be explained in part by the inability of the H19-expressing cells to induce the cyclin-dependent kinase inhibitor p57(kip2) in response to serum stress. Our results favor the possible role of the H19 gene in promoting cancer progression, angiogenesis, and metastasis.

Use of H19 regulatory sequences for targeted gene therapy in cancer

We present a tumor gene therapy approach based on the use of regulatory sequences of the H19 gene that are differentially expressed between normal and cancer cells. We constructed expression vectors carrying the gene for the A fragment of diphtheria toxin (DT-A) or herpes simplex virus thymidine kinase (HSV-tk), under the control of a 814 bp 5'-flanking region of the H19 gene. The cell killing activity of these constructs was in accordance with the relative activity of the H19 regulatory sequences in the transfected cells. We evaluated the therapeutic potential of the gene expression constructs driven by H19 regulatory sequences in an animal model of bladder cancer induced by subcutaneous injection of syngeneic bladder tumor cell lines. Intratumoral injection of these constructs caused a significant suppression of subcutaneous tumor growth, with no obvious toxicity toward the host.

Analysis of differentially expressed genes in hepatocellular carcinoma using cDNA arrays

Hepatocellular carcinoma (HCC) is characterized by multiple somatic mutations, including DNA rearrangements, that affect many cell-growth regulatory pathways. Many genes differentially expressed in HCC have been reported previously, but the patterns of expression varied significantly between patients who bore different risk factors for HCC. To identify genes whose differential expression could serve as a "signature" for diagnosis and prognosis of HCC, we performed analyses of differentially expressed genes in three cases of HCC with different risk factors using the Atlas Human Cancer cDNA Expression Arrays. Among all 597 genes present on the array, only three were found to be coordinately differentially expressed in all three HCC cases, in agreement with published data. These three genes, Cu/Zn superoxide dismutase, osteonectin/secreted protein acidic and rich in cysteine, and matrix metalloproteinase 14, could serve as candidates for the HCC "signature." Ten genes were found to be coordinately differentially expressed in only two of three tested HCC cases. On the other hand, many genes that had been reported previously as differentially expressed in HCC failed to show the described pattern of expression in this group. The results of this study confirm the great variability in gene-expression patterns in HCC and establish the utility of the array technology for identifying both the HCC signature genes and individual gene-expression patterns for purposes of patient-oriented therapy.

The imprinted H19 gene is a marker of early recurrence in human bladder carcinoma

AIMS

To investigate the expression of the imprinted oncofetal H19 gene in human bladder carcinoma and to examine the possibility of using it as a tumour marker, similar to other oncofetal gene products.

METHODS

In situ hybridisation for H19 RNA was performed on 61 first biopsies of bladder carcinoma from Hadassah Medical Centre in Jerusalem. The intensity of the reaction and the number of tumour cells expressing H19 in each biopsy were evaluated in 56 patients, excluding biopsies with carcinoma in situ. The medical files were searched for demographic data and disease free survival.

RESULTS

More than 5% of cells expressed H19 in 47 of the 56 (84%) biopsies. There was a decrease in the number of cells expressing H19 with increasing tumour grade (loss of differentiation) (p = 0.03). Disease free survival from the first biopsy to first recurrence was significantly shorter in patients with tumours having a larger fraction of H19 expressing cells, controlling for tumour grade. This was also supported by the selective analysis of tumour recurrence in patients with grade I tumours.

CONCLUSIONS

It might be possible to use H19 as a prognostic tumour marker for the early recurrence of bladder cancer. In addition, for the gene therapy of bladder carcinoma that is based on the transcriptional regulatory sequences of H19, the expression of H19 in an individual biopsy could be considered a predictive tumour marker for selecting those patients who would benefit from this form of treatment.

Use of transcriptional regulatory sequences of telomerase (hTER and hTERT) for selective killing of cancer cells

Telomerase (hTER and hTERT) plays a crucial role in cellular immortalization and carcinogenesis. Telomerase activity can be detected in about 85% of different malignant tumors, but is absent in most normal cells. In situ hybridization analysis showed that high levels of hTER and hTERT expression are present in bladder cancer, while no signal was detected in normal tissue. Therefore, in this work we propose to use hTER and hTERT transcriptional regulatory sequences to control the expression of a cytotoxic gene in bladder tumor cells, resulting in the selective destruction of this cell population. Expression vectors containing the diphtheria toxin A-chain (DT-A) gene were linked to hTER and hTERT transcriptional regulatory sequences, respectively. Inhibition of protein synthesis occurred in bladder and hepatocellular carcinoma cells transfected with the plasmids containing the DT-A gene under the control of the hTER or hTERT promoters in correlation with their activity. These studies support the feasibility of using hTER and hTERT transcriptional regulatory sequences for targeted patient-oriented gene therapy of human cancer.

The imprinted H19 gene is a marker of early recurrence in human bladder carcinoma

AIMS

To investigate the expression of the imprinted oncofetal H19 gene in human bladder carcinoma and to examine the possibility of using it as a tumour marker, similar to other oncofetal gene products.

METHODS

In situ hybridisation for H19 RNA was performed on 61 first biopsies of bladder carcinoma from Hadassah Medical Centre in Jerusalem. The intensity of the reaction and the number of tumour cells expressing H19 in each biopsy were evaluated in 56 patients, excluding biopsies with carcinoma in situ. The medical files were searched for demographic data and disease free survival.

RESULTS

More than 5% of cells expressed H19 in 47 of the 56 (84%) biopsies. There was a decrease in the number of cells expressing H19 with increasing tumour grade (loss of differentiation) (p = 0.03). Disease free survival from the first biopsy to first recurrence was significantly shorter in patients with tumours having a larger fraction of H19 expressing cells, controlling for tumour grade. This was also supported by the selective analysis of tumour recurrence in patients with grade I tumours.

CONCLUSIONS

It might be possible to use H19 as a prognostic tumour marker for the early recurrence of bladder cancer. In addition, for the gene therapy of bladder carcinoma that is based on the transcriptional regulatory sequences of H19, the expression of H19 in an individual biopsy could be considered a predictive tumour marker for selecting those patients who would benefit from this form of treatment.

Characterization of human and mouse H19 regulatory sequences

H19 is expressed in a large percentage of bladder tumors, but not expressed in healthy bladder tissue. The aim of this study is to define H19 optimal transcriptional regulatory sequences in tumor cells, which can potentially be used to control expression of a toxin gene in constructs to be used in bladder cancer gene therapy trials in mice and human. Transient expression assays revealed that elements responsible for promoter activity are contained within the 85 bp upstream region. The transcriptional activity of this region was strongly inhibited by the methylation of the Hpa II sites. A modest cell specificity is conferred by the upstream sequences. The human and murine promoter activities were significantly increased by the human H19 4.1 kb enhancer sequence. The 85 bp H19 upstream region contains all the elements to interact with the enhancer. We showed that the human H19 promoter is highly active in a murine bladder carcinoma cell line, justifying its use to drive the expression of a cytotoxin gene in gene therapy trials in mice.

The expression of the H19 gene and its function in human bladder carcinoma cell lines

The human H19 gene is a paternally imprinted oncofetal gene, highly expressed in several fetal tissues, down-regulated in nearly all adult tissues but re-expressed in carcinomas of tissues which express the gene in fetal life. It has no known protein product and till today, no function could be designated to H19 RNA. Cells derived from bladder carcinomas and hepatocellular carcinomas were transfected with plasmids carrying a luciferase reporter gene under the control of a 800 nucleotides long promoter region of the H19 gene either alone or together with different parts of a 5 kb downstream region, previously shown to possess enhancer activity. Our results provide evidence that three regions of the 3' downstream sequence can independently stimulate the H19 promoter activity in a tissue and cell specific manner. The growth rate of two cell populations, both derived from the same bladder carcinoma cell line and which differ in their H19 RNA content, were compared. The cells with a high H19 RNA level stopped their proliferation after 48 h when cultivated in a low serum containing media while the cells lacking H19 RNA continued their proliferation for at least an additional 48 h period.

Expression of the imprinted H19 oncofetal RNA in epithelial ovarian cancer

STUDY

To examine the expression of the imprinted maternally expressed H19 gene in benign, low malignant potential (borderline) and malignant surface epithelial ovarian tumors.

DESIGN

In situ hybridization for H19 RNA using S-labeled and digoxigenin-labeled probes was performed on paraffin sections of ovarian surface epithelial tumors. The serous tumors included nine section cystadenomas, twelve serous tumors of low malignant potential and twenty serous carcinomas, grade I-IIII (FIGO classification). A smaller group included two mucinous cystadenomas, four mucinous tumors of low malignant potential and two mucinous cystadenocarcinomas.

RESULTS

H19 expression was found to be positive in 6/9 (67%) serous cystadenomas, 9/12 (75%) of serous tumors of low malignant potential and 13/20 (65%) of invasive serous carcinomas. Expression in mucinous tumors was confined to the stroma beneath the epithelial lining.

CONCLUSION

H19 is expressed in the majority of serous epithelial tumors. Taking into consideration the high percentage of H19 expressing serous ovarian neoplasms we suggest that H19 RNA may be used as an adjuvant tumor marker for the diagnosis and mainly for staging and follow-up of patients with serous ovarian carcinoma.

The dynamics of the imprinted H19 gene expression in the mouse model of bladder carcinoma induced by N-butyl-N-(4-hydroxybutyl)nitrosamine

The imprinted H19 gene product is an oncofetal RNA molecule in humans. It is expressed in fetal bladder, down-regulated postnatally and is re-expressed in human bladder carcinoma. This study was designed to investigate the dynamics of the expression of H19 in the mouse bladder carcinoma induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) and its relation to stages of neoplastic transformation. BBN was administered to mice in the drinking water for 26-28 weeks. The bladders were removed at 5-10 week intervals for histopathological examination and for in situ hybridization for H19 RNA, using a 35S-labeled probe. Following BBN administration expression of H19 first appeared after 5 weeks in the lamina propria adjacent to the basement membrane, concomitant with mucosal hyperplasia. At 11 weeks focal expression was noted in epithelial cells. Invasive carcinomas, of the transitional and squamous sub-types, were seen after 20 weeks and more of BBN administration. At this stage H19 expression was observed in scattered tumor cells, in the connective tissue stroma of the tumor and in the lamina propria underlying the remaining hyperplastic/dysplastic mucosa. Abundant expression of H19 was evident in fetal bladder but was absent in normal adult bladder. We conclude that, similar to humans, the H19 gene product is an oncofetal RNA molecule in the experimental mouse model of bladder carcinoma. In this model H19 is expressed in the connective tissue of the lamina propria prior to its expression in epithelial cells, concurrent with preneoplastic changes in the transitional epithelium of the bladder.

The effect of retinoic acid on the activation of the human H19 promoter by a 3' downstream region

The human H19 is paternally imprinted (maternally expressed). It is transcribed by RNA pol II, but has no protein product. Its function is unknown. We showed that the transcription of the human H19 gene is under the simultaneous control of both a 5' upstream (promoter) region and a 3' downstream region in cell lines derived from human choriocarcinomas. Moreover, the activation of the H19 promoter by retinoic acid in cells derived from human testicular germ cell tumors is dependent upon the 3' downstream region. The possibility that the action of retinoic acid on the H19 promoter is an indirect one and involves a member of the AP2 transcription factor family is discussed.

Imprinted H19 oncofetal RNA is a candidate tumour marker for hepatocellular carcinoma

AIMS/BACKGROUND

To study the expression of the H19 gene in hepatocellular carcinoma. H19 is an imprinted, maternally expressed gene, which is tightly linked, both physically and functionally, to the paternally expressed insulin-like growth factor 2 (IGF II). IGF II is known to be involved in liver carcinogenesis. H19 was first discovered in the fetal mouse liver to be under the same regulatory genes as alpha fetoprotein (alpha FP), a widely used tumour marker for hepatocellular carcinoma.

METHODS

Using both radioactive and non-radioactive in situ hybridisation, the expression of the H19 gene was compared with the presence of alpha FP, as demonstrated by immunohistochemistry, in 18 cases of hepatocellular carcinoma.

RESULTS

H19 expression was present in 13 of 18 cases, whereas staining for alpha FP was positive in only nine of 18 cases. Concordance was found in 12 of 18 tumours (66.7%). In general, the staining pattern for H19 was more diffuse than the immunohistochemical staining for alpha FP.

CONCLUSIONS

The addition of a non-radioactive in situ hybridisation assay for H19 RNA to the panel of tumour markers used for the histopathological and cytological diagnosis of hepatocellular carcinoma might be useful.

The distribution of the vWF alleles and genotypes in the Palestinian population

Short tandem repeat (STR) loci amplified by PCR are known as a useful tool for individual identification and paternity testing. Direct PCR amplification from small amounts of whole blood is a rapid and convenient method for population screening for STR and VNTR markers. The allele frequencies of the vWF locus were determined for 127 unrelated Palestinians. Co-dominant segregation was observed in 20 mother/child pairs. Nine alleles were observed, with frequencies ranging from 0.004 to 0.327. Heterozygosity was 79%, and discrimination power was 0.927.

Mutually co-operative interactions between modulators of P-glycoprotein

We measured the effects of combinations of verapamil, vinblastine, mefloquine, and tamoxifen, all being modulators of the multidrug resistance pump, P-glycoprotein, on the accumulation of labelled daunomycin into multidrug-resistant P388 leukemia cells at 37 degrees C. We found that, contrary to our initial expectations (based on Ayesh, Shao and Stein (1996) Biochim. Biophys. Acta 1316, 8), vinblastine, mefloquine, and tamoxifen all appeared to interact with one another synergistically, i.e. by the kinetics of a non-competitive interaction. A simple kinetic analysis showed that pairs of co-operating modulators can give apparent non-competitive behaviour, but refined kinetic analysis enables the two types of interaction to be distinguished. The modulators vinblastine, mefloquine, and tamoxifen thus appear to co-operate with one another in pairs to bring about reversal of P-glycoprotein. This may have important implications for the design of new modulators of P-glycoprotein.

The product of the imprinted H19 gene is an oncofetal RNA

AIMS/BACKGROUND

The H19 gene is an imprinted, maternally expressed gene in humans. It is tightly linked and coregulated with the imprinted, paternally expressed gene of insulin-like growth factor 2. The H19 gene product is not translated into protein and functions as an RNA molecule. Although its role has been investigated for more than a decade, its biological function is still not understood fully. H19 is abundantly expressed in many tissues from early stages of embryogenesis through fetal life, and is down regulated postnatally. It is also expressed in certain childhood and adult tumours. This study was designed to screen the expression of H19 in human cancer and its relation to the expression of H19 in the fetus.

METHODS

Using in situ hybridisation with a [35S] labelled probe, H19 mRNA was detected in paraffin wax sections of fetal tissues from the first and second trimesters of pregnancy and of a large array of human adult and childhood tumours arising from these tissues.

RESULTS

The H19 gene is expressed in tumours arising from tissues which express this gene in fetal life. Its expression in the fetus and in cancer is closely linked with tissue differentiation.

CONCLUSIONS

Based on these and previous data, H19 is neither a tumour suppressor gene nor an oncogene. Its product is an oncofetal RNA. The potential use of this RNA as a tumour marker should be evaluated.

Drug accumulation in the presence of the multidrug resistance pump: dissociation between verapamil accumulation and the action of P-glycoprotein

We studied the interaction between the multidrug transporter, P-glycoprotein, and two compounds that interact with it: vinblastine, a classical substrate of the pump, and verapamil, a classical reverser. Steady-state levels of accumulation of these two drugs were determined in a multidrug resistant P388 leukemia cell line, P388/ADR. The time course of accumulation of these drugs, and the effect of energy starvation and the presence of chloroquine on the level of their steady-state accumulation were quite disparate. Vinblastine inhibited the accumulation of verapamil whereas it enhanced the accumulation of daunomycin, another classic substrate of P-glycoprotein. Verapamil did not compete with the intracellular binding sites of vinblastine. In all these aspects, vinblastine behaved as a typical substrate of P-glycoprotein but verapamil did not. Our data suggest that verapamil is a reverser of P-glycoprotein but that its intracellular accumulation is not affected by this membrane-bound transporter.

Reversal of P-glycoprotein is greatly reduced by the presence of plasma but can be monitored by an ex vivo clinical assay

The effects of nine reversers of P-glycoprotein on the uptake of daunomycin into MDR1-transfected P388 cells were quantitatively determined in undiluted human or mouse plasma and compared with their effects when measurements are made in a conventional cell culture medium (RPMI 1640) containing only 10% serum. Plasma diminished or greatly diminished the effectiveness of the reversers, reductions of up to 20-fold being found for reversers (cyclosporin A, prochlorperazine and amiodarone) that have been used in clinical trials, although quinidine was almost as effective in plasma as in cell culture medium containing 10% fetal calf serum. Human or bovine serum albumin could mimic the effect of whole plasma. When measurements of the effectiveness of the reverser cyclosporin A were made in an ex vivo assay, using these P388 cells, complete accord was found between such ex vivo determinations and cyclosporin A's effectiveness in vivo, as monitored by its ability to increase the accumulation of vinblastine in mouse kidney tissue. The ex vivo assay was shown to be suitable to monitor the effectivity of reversers present in plasma taken from patients receiving quinidine and cyclosporine A in routine clinical treatment.

Co-operative, competitive and non-competitive interactions between modulators of P-glycoprotein

We measured the effects of individual modulators and of pairs of modulators of the multidrug resistance pump, P-glycoprotein, on the accumulation of labelled daunomycin into multidrug-resistant P388 leukemia cells at 37 degrees C and developed a kinetic analysis which enables such data to be modelled in terms of co-operative, competitive or non-competitive interaction between pairs of modulators. The modulators verapamil, cyclosporin and trifluoperazine interacted with P-glycoprotein as single molecules, while vinblastine, mefloquine, dipyridamole, tamoxifen and quinidine displayed Hill numbers close to 2, suggesting that pairs of modulator molecules need to act together in order to bring about effective reversal of P-glycoprotein. When the modulators were presented to P-glycoprotein in pairs, we found examples of both competitive and non-competitive behaviour. We interpret these results on a model in which two modulatory sites exit on the MDR pump. To one of these, mefloquine, vinblastine and tamoxifen bind preferentially; to the other, verapamil, dipyridamole, trifluoperazine and quinidine bind (but mefloquine and tamoxifen only weakly if at all). Cyclosporin A can interact with both sites.

Kinetic parameters for reversal of the multidrug pump as measured for drug accumulation and cell killing

We determined the kinetic parameters that describe the effect of 20 different modulators of the multidrug resistance pump on the reversal of cytotoxin accumulation in a resistant strain of P388 leukemia cells (P388/ADR), and on the reversal of cell killing for these cells. When measured by a direct comparison of the amplitude of the pertinent protocol (accumulation or cell killing), the Ki for reversal of accumulation was generally some four or five times larger than that for reduction of cytotoxicity. We showed that this was only an apparent discrepancy, since a full theoretical analysis of the two protocols allowed the intrinsic Ki to be obtained for the two procedures and these computed Ki values were then almost identical. We found that for six of the modulators studied (namely, cyclosporin A, quinidine, dipyridamole, propafenone, mefloquine, tamoxifen) the extent of pump reversal should be better than 90% at tolerated plasma levels culled from the literature.

Saturation reversal of the multidrug pump using many reversers in low-dose combinations

Multidrug resistance in cancer cells, in cell culture and in the clinic, is often associated with a membrane protein (the multidrug resistance pump or P-glycoprotein) that pumps out anti-cancer drugs as fast as they enter the cell. This pump is blocked by a range of well-known pharmaceuticals that reverse drug resistance. We have investigated whether effective reversal of drug resistance could be achieved by using many reversers together, each at a low dose relative to its maximal tolerated plasma level. We measured in cell culture, using resistant P388 cells in suspension, the extent of reversal of the accumulation of two labeled cytotoxins (vinblastine and daunomycin). We fitted the data to a modified Michaelis-Menten equation and extracted the half-inhibition constants for 18 reversers acting on the pump. We measured also the reversal of resistance in a cell growth assay using incorporation of labeled thymidine. We showed that these drugs in groups of up to 18 together, each drug being at a low dose, in many cases well-tolerated in humans, had additive effects so that the combination was as effective as any of the drugs present singly. This was the case both for reversal of cell accumulation and for the effects of cytotoxins on cell growth. Our data show that a low-dose multidrug approach to saturation reversal of the multidrug pump is feasible in cell culture and provide the initial experimental basis for the development of an effective regime of such combination reversal therapy.