P-362 The association between pregnancy-test day serum progesterone in IVF pregnancies and obstetrical complications

Study question

Is there an association between pregnancy-test day serum progesterone level in IVF pregnancies and late gestational complications?

Summary answer

Low serum progesterone on pregnancy diagnosis day is independently associated with a higher prevalence of preeclampsia.

What is known already

Low first trimester arbitrary serum progesterone is associated with early pregnancy complications such as ectopic pregnancies and miscarriages. IVF pregnancies are associated with higher prevalence of obstetrical complications such as preterm birth, preeclampsia and small for gestational age. Different patient and treatment parameters such as age, diagnosis, peak blood Estradiol level, endometrial thickness, fresh or frozen embryo transfer are associated with obstetrical complications. Progesterone is a potent immunomodulator that can affect the inflammatory pathway and trophoblast invasion. Little is known about the association between early pregnancy progesterone level and obstetrical complications, with conflicting results.

Study design, size, duration

A cohort study reviewing fertility and delivery files of all singleton live births from successfully treated infertile patients, who underwent ovarian stimulation, IVF and fresh embryo transfer in a tertiary medical center between 2008 and 2018.

Participants/materials, setting, methods

Serum progesterone concentration was measured with the first serum hCG on 4 + 0 gestational week (14 days after oocyte retrieval) under luteal support with vaginal progesterone. Pregnancy-test day serum progesterone was categorized in quartiles. The prevalence of obstetrical complications including gestational diabetes mellitus, preterm birth, preeclamsia, small for gestational age, post-partum hemorrhage and neonatal ICU hospitalization was compared between the four groups. Confounders were adjusted for by multivariate analysis.

Main results and the role of chance

719 singleton live births were included. The four serum progesterone quartiles were: Q1:3-44 nmol/L(n = 180); Q2:45-107 nmol/L(n = 180); Q3:108-223 nmol/L(n = 178); Q4:225-808nmol/L(n = 181). Patients with lower progesterone levels (Q1) had significantly more IVF treatments, lower peak estradiol level, fewer mature follicles and frozen embryos. The incidence of preterm labor, gestational diabetes mellitus, small-for-gestational-age, post-partum hemorrhage, placental abruption or neonatal ICU administration did not differ between the groups. Patients with lower serum progesterone had higher incidence of preeclampsia (9.44% in Q1, 2.78% in Q2, 2.81% in Q3 and 3.31% in Q4, P = 0.0046). On multivariate analysis, controlling for age, gravidity, treatment number, number of oocytes, peak follicular estradiol and progesterone, Q1 progesterone level was independently associated with an increased risk of preeclampsia (estimated OR = 3.27 95% CI 1.455-7.299).

Limitations, reasons for caution

Retrospective design, vaginal progesterone luteal support administration.

Wider implications of the findings

Low serum progesterone on pregnancy diagnosis day in gestations resulting from fresh ET is associated with a significantly higher prevalence of preeclampsia, possibly because of aberrant placentation and vascular development. This association is important for the obstetrical management, preeclampsia risk assessment, and administration of preventive therapy.

Trial registration number

not applicable

P-770 Is there an association between blood hCG elevation rate in very early IVF pregnancy and adverse pregnancy outcomes?

Study question

Is a slow elevation rate between the first and second hCG values following a successful fresh IVF cycle associated with long-term pregnancy outcomes?

Summary answer

A slow rate of hCG elevation in early IVF pregnancies is associated with an increased risk for low birth weight neonates.

What is known already

IVF pregnancies are associated with higher prevalence of late obstetrical complications such as preterm birth, preeclampsia and small for gestational age. Different baseline characteristics and treatment parameters are associated with obstetrical complications. Abnormal, mostly slow, hCG elevation patterns have been strongly associated with short-term adverse pregnancy outcomes such as non-viability, miscarriage, early fetal demise and ectopic pregnancies. However, the long-term impact of slow hCG elevation rate on pregnancies that do continue to term is unknown.

Study design, size, duration

Single center cohort study between 2008-2019 including 703 fresh cycles resulting in live singleton birth. Full obstetrical data for these pregnancies was available.

Participants/materials, setting, methods

The first blood hCG measurement was performed 14±1.4 days after ovum pick-up (OPU), and the second one 48-72h later. The slope between the two measurements was calculated and adjusted per day. Slow hCG elevation was defined as a slope value below the 10th percentile. Maternal and short-term neonatal outcomes were compared between cycles with a slow elevation (n = 71) and a “normal” elevation (n = 632) in hCG values. Multivariate analysis was used to control for potential confounders.

Main results and the role of chance

There were no differences between the slow and normal hCG elevation groups in maternal age, numbers of retrieved oocytes, ICSI rates, number of transferred and usable embryos, and gestational age at delivery. Neonates from cycles with a slow hCG elevation weighed significantly less (2876±619 gr vs. 3083±553 gr, p < 0.005) and were at a higher risk (21% vs. 12%, OR = 1.96, 95% CI 1.06-3.64) of having low birth weight (LBW) (below 2500 grams). Women with slow hCG elevation rate had more hypertension-preeclampsia related complications (11% vs. 6%, p < 0.05), although barely reaching statistical significance in the multivariate analysis (OR = 1.76, 95% CI 1.0-3.6).

Limitations, reasons for caution

Retrospective design, single center, applicability to fresh cycles only.

Wider implications of the findings

Very early (5th week) initial blood hCG elevation slope, measured only in IVF gestations, might be a novel marker for identifying patients at risk for hypertensive complications during pregnancy and low birth-weight neonates. Tighter prenatal care for these patients could potentially reduce pregnancy complications and improve long-term outcome.

Trial registration number

not applicable

When cancer meets quantum mechanics

To date, classical deterministic Newtonian physics has been used by biologists to describe living processes. However, it is increasingly appreciated that the probabilistic view offered by quantum mechanics more accurately describes the behavior of atoms and materials in all systems. Here, we discuss how the concepts of quantum mechanics can be applied to biological processes involved in cancer. We present a concise summary inspired by Heisenberg's Uncertainty Principle to describe our «Genetic Environmental Field Hypothesis». Combining the uncertainties of genetic changes as expressed by epigenetic changes and/or somatic mutations with the uncertainties of environmental changes, cells may become cancerous as a way to increase entropy. Throughout the paper we will utilize the H19 gene system as an example. Using the concepts of quantum mechanics to describe oncological processes may provide novel directions in our understanding of cancer.

The H19 Long non-coding RNA in cancer initiation, progression and metastasis - a proposed unifying theory

The imprinted oncofetal long non-coding RNA (lncRNA) H19 is expressed in the embryo, down-regulated at birth and then reappears in tumors. Its role in tumor initiation and progression has long been a subject of controversy, although accumulating data suggest that H19 is one of the major genes in cancer. It is actively involved in all stages of tumorigenesis and is expressed in almost every human cancer. In this review we delineate the various functions of H19 during the different stages in the complex process of tumor progression. H19 up-regulation allows cells to enter a "selfish" survival mode in response to stress conditions, such as destabilization of the genome and hypoxia, by accelerating their proliferation rate and increasing overall cellular resistance to stress. This response is tightly correlated with nullification, dysfunction or significant down-regulation of the master tumor suppressor gene P53. The growing evidence of H19's involvement in both proliferation and differentiation processes, together with its involvement in epithelial to mesenchymal transition (EMT) and also mesenchymal to epithelial transition (MET), has led us to conclude that some of the recent disputes and discrepancies arising from current research findings can be resolved from a viewpoint supporting the oncogenic properties of H19. According to a holistic approach, the versatile, seemingly contradictory functions of H19 are essential to, and differentially harnessed by, the tumor cell depending on its context within the process of tumor progression.

The non-coding RNAs of the H19-IGF2 imprinted loci: a focus on biological roles and therapeutic potential in Lung Cancer

Since it was first described, the imprinted cluster 11p15.5 has been reported to be deregulated in a variety of pediatric and adult cancers including that of the lung. Both protein coding and non-coding genes functioning as oncogenes or as tumor suppressor genes reside within this cluster. Oncomirs that can function as oncogenes or as tumor suppressors have also been reported. While a complete account of the role played by the 11p15.5 imprinted cluster in lung cancer is beyond the scope of this review, we will focus on the role of the non-coding RNAs processed from the H19-IGF2 loci. A special emphasis will be given to the H19/miR-675 gene locus. Their potential diagnostic and therapeutic use in lung cancer will be described.

Paracetamol treatment of patent ductus arteriosus in preterm infants

OBJECTIVE

To determine the effectiveness of paracetamol in closing patent ductus arteriosus (PDA) in preterm infants of our population.

STUDY DESIGN

Infants with symptomatic PDA who failed or could not get ibuprofen treatment, and who were candidates for surgical ligation, were administered oral paracetamol 15 mg kg⁻¹ every 6h, for up to 7 days and were monitored for clinical, echocardiographic and laboratorial courses.

RESULT

Seven infants, between 24-27 weeks' gestation, were included. In four the DA was closed while treated by paracetamol-in one of them the DA reopened, treated with paracetamol again, and closed. In one infant, the DA almost closed, symptoms disappeared, and the DA subsequently closed spontaneously later. Two needed surgical ligation. There were no hematologic or biochemical abnormalities.

CONCLUSION

Although there is the possibility that PDA may have closed spontaneously, it is proposed that paracetamol could contribute to the closure of PDA in preterm infants.

Oncofetal H19 RNA promotes tumor metastasis

The oncofetal H19 gene transcribes a long non-coding RNA(lncRNA) that is essential for tumor growth. Here we found that numerous established inducers of epithelial to mesenchymal transition(EMT) also induced H19/miR-675 expression. Both TGF-β and hypoxia concomitantly induced H19 and miR-675 with the induction of EMT markers. We identified the PI3K/AKT pathway mediating the inductions of Slug, H19 RNA and miR-675 in response to TGF-β treatment, while Slug induction depended on H19 RNA. In the EMT induced multidrug resistance model, H19 level was also induced. In a mouse breast cancer model, H19 expression was tightly correlated with metastatic potential. In patients, we detected high H19 expression in all common metastatic sites tested, regardless of tumor primary origin. H19 RNA suppressed the expression of E-cadherin protein. H19 up-regulated Slug expression concomitant with the suppression of E-cadherin protein through a mechanism that involved miR-675. Slug also up-regulated H19 expression and activated its promoter. Altogether, these results may support the existence of a positive feedback loop between Slug and H19/miR-675, that regulates E-cadherin expression. H19 RNA enhanced the invasive potential of cancer cells in vitro and enhanced tumor metastasis in vivo. Additionally, H19 knockdown attenuated the scattering and tumorigenic effects of HGF/SF. Our results present novel mechanistic insights into a critical role for H19 RNA in tumor progression and indicate a previously unknown link between H19/miR-675, Slug and E-cadherin in the regulation of cancer cell EMT programs.

DNA based therapy with diphtheria toxin-A BC-819: a phase 2b marker lesion trial in patients with intermediate risk nonmuscle invasive bladder cancer

PURPOSE

H19 is a paternally imprinted oncofetal gene expressed in various embryonic tissues and in 85% of bladder tumors but suppressed in the adult healthy bladder. BC-819 is a DNA plasmid that carries the gene for diphtheria toxin-A under regulation of the H19 promoter sequence. We assessed the efficacy and toxicity of intravesical BC-819 instillations to prevent tumor recurrence and ablate a marker lesion in a phase 2b trial.

MATERIALS AND METHODS

A total of 47 patients with recurrent, multiple nonmuscle invasive bladder tumors in whom prior intravesical therapy had failed underwent transurethral resection of all except 1 marker tumor. Patients expressing H19 received a 6-week induction course of intravesical BC-819. Patients who achieved a complete response (absent new tumors at 3 months) were given 3 maintenance courses of 3-weekly instillations every 3 months.

RESULTS

All patients were evaluable for adverse effects and 39 were evaluable for efficacy. Complete tumor ablation was achieved in 33% of patients and in 64% there were no new tumors at 3 months. Median time to recurrence was 11.3 months in all cases but significantly longer (22.1 months) when analyzed by response status at 3 months. Adverse events were mild. The study was limited by the small number of patients.

CONCLUSIONS

BC-819 prevented new tumor growth in two-thirds of the patients and ablated a third of the marker lesions. Prolonged time to recurrence was observed in responding patients. These results along with the good safety profile make BC-819 a potential medication for bladder cancer.

The increasing complexity of the oncofetal h19 gene locus: functional dissection and therapeutic intervention

The field of the long non-coding RNA (lncRNA) is advancing rapidly. Currently, it is one of the most popular fields in the biological and medical sciences. It is becoming increasingly obvious that the majority of the human transcriptome has little or no-protein coding capacity. Historically, H19 was the first imprinted non-coding RNA (ncRNA) transcript identified, and the H19/IGF2 locus has served as a paradigm for the study of genomic imprinting since its discovery. In recent years, we have extensively investigated the expression of the H19 gene in a number of human cancers and explored the role of H19 RNA in tumor development. Here, we discuss recently published data from our group and others that provide further support for a central role of H19 RNA in the process of tumorigenesis. Furthermore, we focus on major transcriptional modulators of the H19 gene and discuss them in the context of the tumor-promoting activity of the H19 RNA. Based on the pivotal role of the H19 gene in human cancers, we have developed a DNA-based therapeutic approach for the treatment of cancers that have upregulated levels of H19 expression. This approach uses a diphtheria toxin A (DTA) protein expressed under the regulation of the H19 promoter to treat tumors with significant expression of H19 RNA. In this review, we discuss the treatment of four cancer indications in human subjects using this approach, which is currently under development. This represents perhaps one of the very few examples of an existing DNA-based therapy centered on an lncRNA system. Apart from cancer, H19 expression has been reported also in other conditions, syndromes and diseases, where deregulated imprinting at the H19 locus was obvious in some cases and will be summarized below. Moreover, the H19 locus proved to be much more complicated than initially thought. It houses a genomic sequence that can transcribe, yielding various transcriptional outputs, both in sense and antisense directions. The major transcriptional outputs of the H19 locus are presented here.

Development of targeted therapy for a broad spectrum of solid tumors mediated by a double promoter plasmid expressing diphtheria toxin under the control of IGF2-P4 and IGF2-P3 regulatory sequences

BACKGROUND

The human IGF2-P4 and IGF2-P3 promoters are highly active in a variety of human cancers, while existing at a nearly undetectable level in the surrounding normal tissue. Thus, a double promoter DTA-expressing vector was created, carrying on a single construct two separate genes expressing the diphtheria toxin a-fragment (DTA), from two different regulatory sequences, selected from the cancer-specific promoters IGF2-P4 and IGF2-P3.

METHODS

The therapeutic potential of the double promoter toxin vector P4-DTA-P3-DTA was tested in different cancer cells (pancreatic cancer, ovarian cancer and HCC).

RESULTS

The double promoter vector P4-DTA-P3-DTA exhibited superior inhibition activity in different cancer cell lines, compared to the single promoter expression vectors activity.

CONCLUSIONS

Our findings suggest that administration of P4-DTA-P3-DTA has the potential to reach and eradicate tumor cells and thus may help reduce tumor burden, improve the quality of life of the patients; and prolong their life span.

Use of preclinical models to assess the therapeutic potential of new drug candidates for bladder cancer

The purpose of this review is to demonstrate a successful use of preclinical models of bladder cancer to confirm the therapeutic potential of new promising drug candidates. The bladder has long been thought to be an ideal target for investigating therapies. When developing a new antineoplastic pharmaceutical agent, the bladder should be considered for use as an experimental model demonstrating initial proof of concept that if successful can be later assessed in further cancer indications. Non-muscle-invasive bladder carcinoma can be removed by transurethral resection but these cancers tend to recur in most patients. Conventional treatments decrease the recurrence rate but are associated with side effects and frequent failures. Thus, there is an obvious need for the development of highly effective targeted therapies with limited side effects. Accordingly, a double-promoter vector was developed, expressing diphtheria toxin A (DTA) under control of two different regulatory promoter sequences, H19 and IGF2. This vector was then used to transfect and to eradicate tumor cells in bladder cancer models, effectively destroying tumor cells without affecting normal cells. Our studies demonstrate the potential efficacy of the therapeutic vector and should be a solid base for future clinical studies. These models illuminate the path for future investigations of new drug candidates for bladder cancer.

Development of targeted therapy for a broad spectrum of cancers (pancreatic cancer, ovarian cancer, glioblastoma and HCC) mediated by a double promoter plasmid expressing diphtheria toxin under the control of H19 and IGF2-P4 regulatory sequences

BACKGROUND

The human IGF2-P4 and H19 promoters are highly active in a variety of human cancers, while existing at a nearly undetectable level in the surrounding normal tissue. Single promoter vectors expressing diphtheria toxin A-fragment (DTA) under the control regulation of IGF2-P4 or H19 regulatory sequences (IGF2-P4-DTA and H19-DTA) were previously successfully used in cell lines, animal models and recently in human patients with superficial cell carcinoma of the bladder, pancreatic cancer and ovarian cancer (treated with H19-DTA). However this targeted medicine approach may be limited, as not all cancer patients express high levels of H19 and it requires prerequisite diagnostic test for H19. Hence, a double promoter DTA-expressing vector was created, carrying on a single construct two separate genes expressing the diphtheria toxin A-fragment (DTA), from two different regulatory sequences, selected from the cancer-specific promoters H19 and IGF2-P4.

METHODS

H19 and IGF2-P4 gene expression was tested in cell lines of a broad spectrum of different carcinomas (bladder, pancreas, ovary, glioblastoma and HCC), by RT-PCR. The therapeutic potential of the double promoter toxin vector H19-DTA-(IGF2)-P4-DTA was tested in the different cancer cell lines.

RESULTS

The double promoter vector exhibited superior inhibition activity compared to the single promoter expression vectors, in the different cancer cell lines furthermore, the double promoter vector H19-DTA-P4-DTA exhibited augmented-than-additive anti-cancer activity relative to single promoter expression vectors carrying either DTA sequence alone, when tested in a broad spectrum of tumor cells.

CONCLUSIONS

Our findings show that administration of H19-DTA-P4-DTA has the potential to reach tumor cells, deliver its intracellular toxin without targeting normal tissues, and thus may help reduce tumor burden, improve the quality of life of the patient; and prolong their life span. As H19 and IGF2 were expressed in a broad spectrum of different cancers, therefore we propose a double promoter expression approach for treating a variety of tumors expressing H19, IGF2, or both. According to this approach patients may be treated with a single double promoter expression toxin vector which is under the control of the IGF2 and H19 regulatory sequences, differentially expressed in those cancers. As majority of the tumor cells express H19, IGF2, or both, therefore the use of prerequisite diagnostic test will be unnecessary.

Transcriptional targeting of glioblastoma by diphtheria toxin-A driven by both H19 and IGF2-P4 promoters

BACKGROUND

The H19-IGF2 locus is either highly expressed and/or shows aberrant allelic pattern of expression in a large array of human cancers, while rarely expressed in the corresponding normal tissue. Preclinical, clinical studies and human compassionate using a DNA plasmid containing H19 and/or IGF2-P4 regulatory sequences that drive the expression of an intracellular toxin [diphtheria toxin A-fragment (DTA)] have demonstrated promising results in several types of carcinomas. Recently we reported that a single construct that expresses DTA under the control of both H19 and IGF2 P4 promoters showed superior efficacy in vitro as well as in vivo, in comparison to a single promoter construct in bladder carcinoma. Here we extended this approach to glioblastoma and tested the antitumor efficacy of the double promoter DTA-expressing vector (H19-DTA-P4-DTA) in vitro as well as in heterotopic animal model. H19 gene expression was tested by in-situ hybridization (ISH) and by quantitative Real-Time PCR (qRT-PCR) in samples of diffuse glioma.

METHODS

IGF2-P4 gene expression was tested by qRT-PCR as well.

RESULTS

Both H19 and IGF2-P4 transcripts were highly expressed in high grade gliomas. Furthermore, significant H19 expression in other types of primary brain tumors as well as in brain metastases was detected by ISH. Both A172 and U87 human glioblastoma cell lines showed high expression of IGF2-P4 while the A172 cell line showed high expression of H19 RNA as well. H19-DTA-P4-DTA exhibited superior cytotoxic activity compared to the single promoter expression vectors, in U87 and A172 glioblastoma cell lines in vitro and showed antitumoral efficacy in heterotopic glioblastoma animal model.

CONCLUSIONS

Our findings indicate antitumoral efficacy against glioblastoma of the targeted double promoter vector H19-DTA-P4-DTA, both in-vitro and in-vivo. Thus, its test in orthotopic animal model of glioblastoma as well as in clinical trials is warranted.

Regional therapy with DTA-H19 vector suppresses growth of colon adenocarcinoma metastases in the rat liver

Curative surgery is possible in barely 10% of patients with colorectal liver metastases and combined treatment modalities scarcely improve survival in this group of patients. Hence, investigations of new therapeutic modalities are crucial. Overexpression of the H19 gene in liver metastases points to H19 as a target for cancer gene therapy. Here we have evaluated the possibility of regional intra-arterial treatment of liver meta-stases with the DTA-H19 plasmid. Intra-arterial treatment of a total dose of 2.5 mg (repeated injections of 500 µg DTA-H19 plasmid each dose after the first injection of 1000 µg) caused a significant delay in the tumor growth compared to control group. All of the tumors treated with the control vector increased in size, whereas 35.7% of the tumors in the groups treated with a total amount of 2.5 mg DTA-H19 plasmid shrank in size. The present study showed that the DTA-H19 plasmid administered intra-arterially significantly delayed the tumor growth and even resulted in tumor regression in high percentage of the treated animals with liver metastases of colon cancer. Since human liver metastases demonstrated overexpression of the H19 gene, regional administration of the plasmid seems to be a promising therapeutic approach.

Development of targeted therapy for bladder cancer mediated by a double promoter plasmid expressing diphtheria toxin under the control of IGF2-P3 and IGF2-P4 regulatory sequences

BACKGROUND

The human IGF2-P3 and IGF2-P4 promoters are highly active in bladder carcinoma, while existing at a nearly undetectable level in the surrounding normal tissue. A double promoter DTA-expressing vector was created, carrying on a single construct two separate genes expressing diphtheria toxin A-fragment (DTA), from two different regulatory sequences, selected from the cancer-specific promoters IGF2-P3 and IGF2-P4.

METHODS

IGF2-P3 and IGF2-P4 expression was tested in samples of urothelial carcinoma (UC) of the bladder (n=67) by RT-PCR or by ISH. The therapeutic potential of single promoter expression vectors (P3-DTA and P4-DTA) was tested and compared to the double promoter toxin vector P4-DTA-P3-DTA in UC cell lines and in heterotopic and orthotopic animal models for bladder cancer.

RESULTS

Nearly 86% of UC patients highly expressed IGF2-P4 and IGF2-P3, as determined by ISH. The double promoter vector (P4-DTA-P3-DTA) exhibited superior ability to inhibit tumor development by 68% (P=0.004) compared to the single promoter expression vectors, in heterotopic bladder tumors. The average size of the P4-DTA-P3-DTA bladder tumors (in orthotopically treated mice) was 83% smaller (P<0.001) than that of the control group.

CONCLUSIONS

Overall, the double promoter vector exhibited enhanced anti-cancer activity relative to single promoter expression vectors carrying either gene alone. Our findings show that bladder tumors may be successfully treated by intravesical instillation of the double promoter vector P4-DTA-P3-DTA.

Development of targeted therapy for bladder cancer mediated by a double promoter plasmid expressing diphtheria toxin under the control of H19 and IGF2-P4 regulatory sequences

BACKGROUND

The human IGF2-P4 and H19 promoters are highly active in a variety of human cancers (including bladder cancer), while existing at a nearly undetectable level in the surrounding normal tissue.Single promoter vectors expressing diphtheria toxin A-fragment (DTA) under the control regulation of IGF2-P4 or H19 regulatory sequences (IGF2-P4-DTA and H19-DTA) were previously successfully used in cell lines, animal models and recently in human patients with superficial cell carcinoma of the bladder (treated with H19-DTA). However this targeted medicine approach could be limited, as not all cancer patients express high levels of H19. Hence, a double promoter DTA-expressing vector was created, carrying on a single construct two separate genes expressing the diphtheria toxin A-fragment (DTA), from two different regulatory sequences, selected from the cancer-specific promoters H19 and IGF2-P4.

METHODS

H19 and IGF2-P4 gene expression was tested in samples of Transitional Cell Carcinoma (TCC) of the bladder by in-situ hybridization (ISH) and by quantitative Real-Time PCR (qRT-PCR). The therapeutic potential of the double promoter toxin vector H19-DTA-IGF2-P4-DTA was tested in TCC cell lines and in heterotopic and orthotopic animal models of bladder cancer.

RESULTS

Nearly 100% of TCC patients highly expressed IGF2-P4 and H19, as determined by ISH and by qRT-PCR. The double promoter vector exhibited superior tumor growth inhibition activity compared to the single promoter expression vectors, in cell lines and in heterotopic and orthotopic bladder tumors.

CONCLUSIONS

Our findings show that bladder tumors may be successfully treated by intravesical instillation of the double promoter vector H19-DTA-P4-DTA.Overall, the double promoter vector exhibited enhanced anti-cancer activity relative to single promoter expression vectors carrying either gene alone.

Targeting diphtheria toxin and TNF alpha expression in ovarian tumors using the H19 regulatory sequences

BACKGROUND

There are currently no effective therapies for the treatment of ovarian cancer ascites fluid (OCAF). H19 is an RNA oncofetal gene that is present at high levels in human cancer tissues (ovarian cancer and OCAF among them), while existing at a nearly undetectable level in the surrounding normal tissue. There is evidence for a synergistic effect in cell cytotoxicity mediated by TNFα and diphtheria toxin in sensitive and resistant human ovarian tumor cell line. Thus, we tested the cytotoxic effect of TNF-α cytokine, together with the diphtheria toxin, in the therapy of ovarian cancer.

METHODS

The therapeutic potential of toxin vectors carrying the DT-A gene alone (pH19-DTA), or in combination with the TNF-α gene (pH19-TNF-DTA), driven by H19 regulatory sequences were tested in ovarian carcinoma cell lines and in a heterotopic ovarian cancer model.

RESULTS

The toxin vectors showed a high killing capacity when transfected into different ovarian cancer cell lines. In addition, intratumoral injection of the toxin vector into ectopically developed tumors caused 40% inhibition of tumor growth. The killing effect after injection of pH19-TNF-DTA plasmid into ectopically developed tumors was significantly higher than that showed by the pH19-DTA plasmid alone, particularly in diphtheria toxin and TNF resistant tumors.

CONCLUSIONS

These observations may be the first step towards a major breakthrough in the treatment of human ovarian cancer. It should enable us to identify likely non-responders in advance, and to treat patients who are resistant to all known therapies, thereby avoiding treatment failure coupled with unnecessary suffering and cost.

Treatment of ovarian cancer ascites by intra-peritoneal injection of diphtheria toxin A chain-H19 vector: a case report

Introduction

Ovarian cancer ascitic fluid, which contains malignant cells, is usually present in women with an advanced stage disease. There are currently no effective therapies for the treatment of ovarian cancer ascitic fluid. We developed a new therapeutic strategy to target expression of the diphtheria toxin fragment A gene in ovarian tumor cells under the control of H19 regulatory sequences.

Case presentation

A 64-year-old Caucasian woman was diagnosed with a stage IIIc epithelial ovarian cancer. She suffered from progressive disease, accumulation of malignant ascites that needed to be drained weekly, abdominal pain, vomiting, anorexia and severe weakness. Infusion of the diphtheria toxin A chain-H19 plasmid into the peritoneum of our patient resulted in complete resolution of the ascites with minimum adverse events.

Conclusion

On the basis of this preliminary experience, we are currently conducting an extensive Phase I study on a larger number of patients in order to assess the safety and preliminary efficacy of this novel patient-oriented treatment approach.

The oncofetal H19 RNA connection: hypoxia, p53 and cancer

Expression of the imprinted H19 gene is remarkably elevated in a large number of human cancers. Recently, we reported that H19 RNA is up-regulated in hypoxic stress and furthermore, it possesses oncogenic properties. However, the underlying mechanism(s) of these phenomena remain(s) unknown. Here we demonstrate a tight correlation between H19 RNA elevation by hypoxia and the status of the p53 tumor suppressor. Wild type p53 (p53(wt)) prevents the induction of H19 upon hypoxia, and upon its reconstitution in p53(null) cells. The last case is accompanied by a decrease in cell viability. The p53 effect is nuclear and seems independent of its tetramerization. Furthermore, using knockdown and over-expression approaches we identified HIF1-alpha as a critical factor that is responsible for H19 induction upon hypoxia. Knocking down HIF1-alpha abolishes H19 RNA induction, while its over-expression significantly enhances the H19 elevation in p53(null) hypoxic cells. In p53(wt) hypoxic cells simultaneous suppression of p53 and over-expression of HIF1-alpha are needed to induce H19 significantly, while each treatment separately resulting in a mild induction, indicating that the molecular mechanism of p53 suppression effect on H19 may at least in part involve interfering with HIF1-alpha activity. In vivo a significant increase in H19 expression occurred in tumors derived from p53(null) cells but not in p53(wt) cells. Taken together, our results indicate that a functional link exists between p53, HIF1-alpha and H19 that determines H19 elevation in hypoxic cancer cells. We suggest that this linkage plays a role in tumor development.

Development of targeted therapy for ovarian cancer mediated by a plasmid expressing diphtheria toxin under the control of H19 regulatory sequences

Background

Ovarian cancer ascites fluid (OCAF), contains malignant cells, is usually present in women with an advanced stage disease and currently has no effective therapy. Hence, we developed a new therapy strategy to target the expression of diphtheria toxin gene under the control of H19 regulatory sequences in ovarian tumor cells. H19 RNA is present at high levels in human cancer tissues (including ovarian cancer), while existing at a nearly undetectable level in the surrounding normal tissue.

Methods

H19 gene expression was tested in cells from OCAF by the in-situ hybridization technique (ISH) using an H19 RNA probe. The therapeutic potential of the toxin vector DTA-H19 was tested in ovarian carcinoma cell lines and in a heterotopic animal model for ovarian cancer.

Results

H19 RNA was detected in 90% of patients with OCAF as determined by ISH. Intratumoral injection of DTA-H19 into ectopically developed tumors caused 40% inhibition of tumor growth.

Conclusion

These observations may be the first step towards a major breakthrough in the treatment of human OCAF, while the effect in solid tumors required further investigation. It should enable us to identify likely non-responders in advance, and to treat patients who are resistant to all known therapies, thereby avoiding treatment failure.

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 (&lt;0.5 or &gt;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.

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.

H19 and IGF2 gene expression in human normal, hyperplastic, and malignant endometrium

We examined H19 and insulin-like growth factor 2 (IGF2) gene expression in normal endometrium (12 cases), hyperplasia (27 cases), and cancer (27 cases) by non-radioactive in situ hybridization. H19 was not expressed in the epithelium of normal endometrium, but its frequency of expression was 15% in hyperplastic and 60% in neoplastic epithelium. In stroma cells, H19 frequency of expression was 75% in normal endometrium, 55% in hyperplasia, and 37% in carcinoma. According to the grade of endometrial cancer cell differentiation, H19 showed increased frequency and level of expression in the epithelium from well to moderately and poorly differentiated tissues. Our results indicate that H19 expression in epithelial cells of endometrial hyperplasia and cancer merits further investigation and could be useful as a complementary histopathologic and prognostic marker among other modalities in endometrial cancer. IGF2 expression did not appear useful for diagnostic or prognostic purposes.

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.

Nitric oxide synthase immunoreactivity in human bladder carcinoma

AIMS

To study the expression of the endothelial and inducible isoforms of nitric oxide synthase (eNOS and iNOS, respectively) in human bladder carcinoma and schistosomal bladder disease, and to compare it with normal adult and fetal urothelium. Nitric oxide is thought to play a complex role in human carcinogenesis, but has only recently been investigated in bladder cancer.

METHODS

Immunohistochemistry was performed on paraffin wax embedded sections of 33 human bladder carcinomas and five bladder carcinoma cell lines; in addition, seven schistosomal bladder cases and normal and fetal urothelium were investigated. In the cell lines enzymatic activity was examined by the NADPH diaphorase reaction.

RESULTS

Immunoreactivity for eNOS was present in most cells of all 31 cases examined. Immunoreactivity for iNOS was less abundant and was seen in 23 of 25 cases. Similar findings were noted in schistosomal bladder cancer. In the normal bladder mucosa, eNOS immunoreactivity was found only in the superficial cell layer and iNOS was not expressed, whereas in the fetal urothelium immunoreactivity for both isoforms was seen in all cell layers. Enzymatic activity and immunoreactivity for eNOS and iNOS were evident in the five bladder carcinoma cell lines.

CONCLUSIONS

It is possible that NOS plays a role in the differentiation of the transitional epithelium in fetal life, has a biological function in the adult bladder mucosa, and is involved in bladder carcinogenesis. eNOS and iNOS immunoreactivity do not differ in schistosomal and non-schistosomal bladder carcinoma, but resemble the pattern of expression typical of fetal urothelium.

Nitric oxide synthase immunoreactivity in human bladder carcinoma

AIMS

To study the expression of the endothelial and inducible isoforms of nitric oxide synthase (eNOS and iNOS, respectively) in human bladder carcinoma and schistosomal bladder disease, and to compare it with normal adult and fetal urothelium. Nitric oxide is thought to play a complex role in human carcinogenesis, but has only recently been investigated in bladder cancer.

METHODS

Immunohistochemistry was performed on paraffin wax embedded sections of 33 human bladder carcinomas and five bladder carcinoma cell lines; in addition, seven schistosomal bladder cases and normal and fetal urothelium were investigated. In the cell lines enzymatic activity was examined by the NADPH diaphorase reaction.

RESULTS

Immunoreactivity for eNOS was present in most cells of all 31 cases examined. Immunoreactivity for iNOS was less abundant and was seen in 23 of 25 cases. Similar findings were noted in schistosomal bladder cancer. In the normal bladder mucosa, eNOS immunoreactivity was found only in the superficial cell layer and iNOS was not expressed, whereas in the fetal urothelium immunoreactivity for both isoforms was seen in all cell layers. Enzymatic activity and immunoreactivity for eNOS and iNOS were evident in the five bladder carcinoma cell lines.

CONCLUSIONS

It is possible that NOS plays a role in the differentiation of the transitional epithelium in fetal life, has a biological function in the adult bladder mucosa, and is involved in bladder carcinogenesis. eNOS and iNOS immunoreactivity do not differ in schistosomal and non-schistosomal bladder carcinoma, but resemble the pattern of expression typical of fetal urothelium.

Regulatory RNAs

In addition to mRNA, rRNA and tRNA, which play central roles within cells, there are a number of regulatory, non-coding RNAs (ncRNAs). Of varying lengths, ncRNAs have no long open reading frame. While not encoding proteins, they may act as riboregulators, and their main function is posttranscriptional regulation of gene expression. Many ncRNAs have been identified and characterized both in prokaryotes and eukaryotes, and are involved in the specific recognition of cellular nucleic acid targets through complementary base pairing, controlling cell growth and differentiation. Some are associated with the abnormalities in imprinted inheritance that occur in several well-known developmental and neurobehavioral disorders. Other ncRNAs accomplish regulation by modulating the activity of proteins. Several rRNAs are able to sustain enzymatic reactions implicated in the translation process including synthesis of peptide bonds within the ribosome. The different roles played by widely distributed RNAs acting in diverse ways, suggest the flexibility and versality of these molecules in regulatory processes. This review summarizes the available biochemical and structural data on known regulatory RNAs.

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.

The non-coding RNAs as riboregulators

The non-coding RNAs database (http://biobases.ibch.poznan.pl/ncRNA/) contains currently available data on RNAs, which do not have long open reading frames and act as riboregulators. Non-coding RNAs are involved in the specific recognition of cellular nucleic acid targets through complementary base pairing to control cell growth and differentiation. Some of them are connected with several well known developmental and neuro-behavioral disorders. We have divided them into four groups. This paper is a short introduction to the database and presents its latest, updated edition.

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.

Imprinted H19 gene expression in embryogenesis and human cancer: the oncofetal connection

Cancer cells resemble embryonal cells morphologically and share with them characteristics such as reduced differentiation, rapid proliferation rate, and increased motility. Genes expressed in embryogenesis, down-regulated with tissue maturation and reexpressed in cancer, are designated as oncofetal genes, and many of them are used as tumor markers. The H19 gene is an imprinted gene that is expressed from the maternal allele and functions as an RNA molecule. It is abundantly expressed in fetal life and down-regulated postnatally. We have shown oncofetal expression of H19 in human cancer. The study of H19 expression in testicular germ cell tumors of adolescents and young adults, which follow lines of differentiation of the conceptus, demonstrates dissociation between level of expression and monoallelic versus biallelic expression, which are two independent oncofetal characteristics of cancer. Expression of the maternally expressed H19 from the paternal allele in the villous cytotrophoblastic cells of the androgenetic complete hydatidiform mole is designated relaxation of imprinting. H19 is abundantly expressed in the fetal bladder mucosa and in carcinoma of the urinary bladder. It is a marker of early recurrence and may be used as a potential basis for gene therapy.

Non-coding, mRNA-like RNAs database Y2K

In last few years much data has accumulated on various non-translatable RNA transcripts that are synthesised in different cells. They are lacking in protein coding capacity and it seems that they work mainly or exclusively at the RNA level. All known non-coding RNA transcripts are collected in the database: http://www. man.poznan.pl/5SData/ncRNA/index.html

Inhibition of bladder carcinoma angiogenesis, stromal support, and tumor growth by halofuginone

We have previously demonstrated that halofuginone, a widely used alkaloid coccidiostat, is a potent inhibitor of collagen alpha1(I) and matrix metalloproteinase 2 gene expression. Halofuginone also suppresses extracellular matrix deposition and cell proliferation. We investigated the effect of halofuginone on transplantable and chemically induced mouse bladder carcinoma. In both systems, oral administration of halofuginone resulted in a profound anticancerous effect, even when the treatment was initiated at advanced stages of tumor development. Although halofuginone failed to prevent proliferative preneoplastic alterations in the bladder epithelium, it inhibited further progression of the chemically induced tumor into a malignant invasive stage. Histological examination and in situ analysis of the tumor tissue revealed a marked decrease in blood vessel density and in both collagen alpha1(I) and H19 gene expression. H19 is regarded as an early marker of bladder carcinoma. The antiangiogenic effect of halofuginone was also demonstrated by inhibition of microvessel formation in vitro. We attribute the profound antitumoral effect of halofuginone to its combined inhibition of the tumor stromal support, vascularization, invasiveness, and cell proliferation.