A novel SARS-CoV-2 Beta RBD DNA vaccine directly targeted to antigen-presenting cells induces strong humoral and T cell responses

Throughout the COVID-19 pandemic, several variants of concern (VoC) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have evolved, affecting the efficacy of the approved COVID-19 vaccines. To address the need for vaccines that induce strong and persistent cross-reactive neutralizing antibodies and T cell responses, we developed a prophylactic SARS-CoV-2 vaccine candidate based on our easily and rapidly adaptable plasmid DNA vaccine platform. The vaccine candidate, referred to here as VB2129, encodes a protein homodimer consisting of the receptor binding domain (RBD) from lineage B.1.351 (Beta) of SARS-CoV-2, a VoC with a severe immune profile, linked to a targeting unit (human LD78β/CCL3L1) that binds chemokine receptors on antigen-presenting cells (APCs) and a dimerization unit (derived from the hinge and CH3 exons of human IgG3). Immunogenicity studies in mice demonstrated that the APC-targeted vaccine induced strong antibody responses to both homologous Beta RBD and heterologous RBDs derived from Wuhan, Alpha, Gamma, Delta, and Omicron BA.1 variants, as well as cross-neutralizing antibodies against these VoC. Overall, preclinical data justify the exploration of VB2129 as a potential booster vaccine that induces broader antibody- and T cell-based protection against current and future SARS-CoV-2 VoC.

Rehospitalizations, repeated aortic surgery, and death in initial survivors of surgery for Stanford type A aortic dissection and the significance of age – a nationwide registry-based cohort study

Background

All patients with type A aortic dissections, regardless of age, are recommended urgent aortic surgery. However, studies exploring long term outcomes in survivors are sparse, and especially, the significance of age on long-term outcomes remain unclear.

Purpose

We described and compared incidences across age groups of post-discharge readmission, repeated aortic surgery, and death in patients who survived surgery and hospitalization for type A aortic dissection.

Methods

Using data from Danish nationwide registries, we identified patients hospitalized with Stanford type A aortic dissections from 2006–2018. Survivors of hospitalization and surgery on the ascending aorta and/or aortic arch comprised the study population (Figure 1). Using cumulative incidence plots taking death into account as a competing risk and Cox regression analysis, we described long-term outcomes (rehospitalizations, repeated aortic surgery, and death) and compared different age groups. The diagnosis of type A aortic dissection in the registries used, was validated from 191 clinical records to have a positive predictive value of 94.8%.

Results

Of 606 initial survivors of surgery and hospitalization with type A aortic dissection, 236 (38.9%) were <60 years old (group I), 194 (32.0%) were 60–69 years old (group II), and 176 (29.1%) were >69 years old (group III). Figure 2 shows cumulative incidences of outcomes according to age. During the first year, 62.5% were re-hospitalized (median number of days hospitalized was 2 days (IQR 1–8 days) and 1.4% underwent repeated aortic surgery with no significant differences across age groups (P=0.68 and P=0.39, respectively). Further, 5.9% died (group I: 3.0%, group II: 8.3%, group III: 7.4%, P=0.04). After 10 years of follow up, 8.0% had undergone repeated aortic surgery (group I: 11.5%, group II: 8.5%, group III: 1.6%, P=0.04) and 10.2% (group I), 17.0% (group II), and 22.2% (group III) had died (P=0.01). In adjusted analyses, no age differences were found in one-year outcomes, while age >69 years (group III) compared with age <60 years (group I) was associated with a lower rate of repeated aortic surgery (hazard ratio 0.17, 95% confidence interval 0.04–0.78) and a higher rate of all-cause mortality (hazard ratio 2.44, 95% confidence interval 1.37–4.34) in the 10-years analysis.

Conclusion

Among survivors of type A aortic dissections, rehospitalizations the first year after discharge were common among all age groups, but survival was high. Repeated aortic surgery was rare, and significantly more common among younger than older patients. Evaluations of quality of life in survivors of type A aortic dissections are needed.

Funding Acknowledgement

Type of funding sources: None.

Abstract 3558: A novel and versatile cytokine empowered DNA vaccine platform with superior immune activating potential

Immunotherapy, in particular Immune Checkpoint Blockade (ICB) has been regarded as the next standard of care for many solid tumor indications. Yet, a significant proportion of patients do not respond to therapy. More specifically, failure of ICB has been linked to the absence of an anti-tumor immune response that can be boosted or revitalized. Cancer vaccines that are designed to elicit such response by educating the host immune system to recognize tumor antigens, are therefore considered a key next generation therapeutic modality for the treatment of human cancers.

Various vaccine platforms have been developed over the years, but recent advances in delivery technologies combined with the intrinsic qualities of the DNA matrix have positioned DNA vaccines as a safe and flexible alternative to other types of vaccine technologies. Vaccibody is developing DNA vaccines that allows specific targeting of tumors antigens to Antigen Presenting Cells (APCs), thus maximizing the elicited immune response.

Here we present a second-generation version of our DNA platform in which our vaccibody molecule can be co-expressed with immune-stimulatory proteins from one plasmid using a multicistronic design. Compared to the vaccibody molecule alone the simultaneous expression of selected immune stimulatory cytokines was shown to boost the overall immune response almost 3-fold to drive a potent anti-tumor response.

These data demonstrate the flexibility and potential of DNA vaccines as well as the advantages of combining an APC targeted delivery of tumor specific antigens together with a local production of immune stimulatory proteins.

Citation Format: Audun Beraas, Pierre Dillard, Judith Jing Wong, Christian Winther Wold, Eirik Solbakken, Linn Guro Oslen, Joel Benjamin Heim, Stalin Chellappa, Agnete Fredriksen, Mikkel Wandahl Pedersen, Stine Granum. A novel and versatile cytokine empowered DNA vaccine platform with superior immune activating potential [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3558.

Sym015: A Highly Efficacious Antibody Mixture against MET-Amplified Tumors

Purpose: Activation of the receptor tyrosine kinase MET is associated with poor clinical outcome in certain cancers. To target MET more effectively, we developed an antagonistic antibody mixture, Sym015, consisting of two humanized mAbs directed against nonoverlapping epitopes of MET.Experimental Design/Results: We screened a large panel of well-annotated human cancer cell lines and identified a subset with highly elevated MET expression. In particular, cell lines of lung cancer and gastric cancer origin demonstrated high MET expression and activation, and Sym015 triggered degradation of MET and significantly inhibited growth of these cell lines. Next, we tested Sym015 in patient- and cell line-derived xenograft models with high MET expression and/or MET exon 14 skipping alterations, and in models harboring MET amplification as a mechanism of resistance to EGFR-targeting agents. Sym015 effectively inhibited tumor growth in all these models and was superior to an analogue of emibetuzumab, a monoclonal IgG4 antibody against MET currently in clinical development. Sym015 also induced antibody-dependent cellular cytotoxicity (ADCC) in vitro, suggesting that secondary effector functions contribute to the efficacy of Sym015.Retrospectively, all responsive, high MET-expressing models were scored as highly MET-amplified by in situ hybridization, pointing to MET amplification as a predictive biomarker for efficacy. Preclinical toxicology studies in monkeys showed that Sym015 was well tolerated, with a pharmacokinetic profile supporting administration of Sym015 every second or third week in humans.Conclusions: The preclinical efficacy and safety data provide a clear rationale for the ongoing clinical studies of Sym015 in patients with MET-amplified tumors. Clin Cancer Res; 23(19); 5923-35. ©2017 AACR.

Abstract P6-12-09: Pan-HER, an antibody mixture with antitumor activity against drug-resistant HER2-overexpressing breast cancers with high ERBB ligand expression

Background: Amplification/overexpression of ERBB receptors and/or ligands has been associated with resistance to anti-HER2 therapies. Pan-HER is a mixture of six antibodies targeting each of the ERBB receptors, EGFR, HER2 and HER3, with synergistic pairs of antibodies. Each pair of antibodies simultaneously blocks ligand binding and/or induces target degradation, thus preventing compensatory mechanisms to anti-ERBB therapies. We examined the antitumor activity of Pan-HER against drug-sensitive and -resistant HER2+ breast cancer cells and xenografts.

Results: Pan-HER exhibited potent growth inhibitory activity against a panel of HER2+ breast cancer cells (BT474, MDA-453, MDA-361, SUM190, HCC1954, UACC893 and SKBR3). Growth inhibition was associated with internalization and degradation of EGFR, HER2 and HER3. Pan-HER was superior to the combination of trastuzumab/pertuzumab (TP) against HER2+/PIK3CA mutant MDA-361, HCC1954, UACC893 and MDA-453 cells. We next compared the effect of Pan-HER against BT474, HCC1954 and MDA-361 xenografts established in nude mice to that of trastuzumab/lapatinib (TL), TP and T-DM1. All treatments were effective across the panel of xenografts. In mice with MDA-361 tumors, Pan-HER and TP were superior to TL. Immunoblot analysis showed significant downregulation of EGFR, HER2 and HER3 only in tumors treated with Pan-HER. After a complete response, treatment was discontinued. Among mice with BT474 xenografts treated with TP, TL and T-DM1, 25-50% of mice exhibited a tumor recurrence within 50 weeks of follow-up, while no recurrences were registered in mice treated with Pan-HER. Tumors recurring after TP and T-DM1 expressed significantly higher HER3 and P-HER3 protein levels and NRG1 mRNA levels. HCC1954 xenografts recurring after T-DM1 also overexpressed NRG1 mRNA compared to tumors before therapy.

We next examined the effect of Pan-HER against trastuzumab-resistant HR6 (BT474) cells (Ritter et al. CCR 2007) and HCC1954 and UACC893 cells with acquired resistance to T-DM1 (TDR; IC50 >5-, >6- and 600-fold in HR6, UACC893-TDR and HCC1954-TDR cells, respectively, vs. parental cells). All T-DM1-resistant cells expressed significantly higher HER3 and P-HER3 protein levels and NRG1 mRNA and protein levels. Treatment with the HER3 neutralizing antibody LJM716 resensitized HR6 and HCC1954-TDR cells to T-DM1, suggesting a causal association between the NRG1-HER3 axis and drug resistance. Mice with HR6 tumors were treated with Pan-HER, TL, TP and T-DM1. Only Pan-HER arrested HR6 tumor growth and downregulated EGFR, HER2, HER3, P-HER3 and P-AKT. Finally, HCC1954-TDR tumors rapidly grew in vivo despite treatment with T-DM1. Administration of Pan-HER to mice bearing HCC1954-TDR xenografts growing in the presence of T-DM1, induced rapid tumor regressions.

Conclusions: These data suggest that multitarget therapeutic interventions, such as Pan-HER, which simultaneously remove and/or block all ERBB receptors and ligands, are a feasible and effective approach against HER2-overexpressing cancers both sensitive and resistant to anti-HER2 therapies.

Citation Format: Schwarz LJ, Hutchinson KE, Estrada MV, Sanders ME, Dugger TC, Formisano L, Guerrero AL, Red-Brewer M, Young CD, Lantto J, Pedersen MW, Kragh M, Horak ID, Arteaga CL. Pan-HER, an antibody mixture with antitumor activity against drug-resistant HER2-overexpressing breast cancers with high ERBB ligand expression [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-12-09.

Cetuximab Resistance in Squamous Carcinomas of the Upper Aerodigestive Tract Is Driven by Receptor Tyrosine Kinase Plasticity: Potential for mAb Mixtures

Squamous cell carcinomas (SCC) arising in upper parts of the aerodigestive tract are among the leading causes of death worldwide. EGFR has been found to play an essential role in driving the malignancy of SCC of the upper aerodigestive tract (SCCUAT), but, despite this, clinical results using a range of different EGFR-targeted agents have been disappointing. Cetuximab is currently the only EGFR-targeted agent approved by the FDA for treatment of SCCUAT. However, intrinsic and acquired cetuximab resistance is a major problem for effective therapy. Thus, a better understanding of the mechanisms responsible for cetuximab resistance is valuable for development of the next generation of antibody therapeutics. In order to better understand the underlying mechanisms of cetuximab resistance in SCCUAT, we established from cetuximab-sensitive models cell lines with acquired resistance to cetuximab by continuous selective pressure in vitro and in vivo Our results show that resistant clones maintain partial dependency on EGFR and that receptor tyrosine kinase plasticity mediated by HER3 and IGF1R plays an essential role. A multitarget mAb mixture against EGFR, HER3, and IGF1R was able to overcome cetuximab resistance in vitro To our surprise, these findings could be extended to include SCCUAT cell lines with intrinsic resistance to cetuximab, suggesting that the triad consisting of EGFR, HER3, and IGF1R plays a key role in SCCUAT. Our results thus provide a rationale for simultaneous targeting of EGFR, HER3, and IGF1R in SCCUAT. Mol Cancer Ther; 15(7); 1614-26. ©2016 AACR.

Detection and strain differentiation of infectious bronchitis virus in tracheal tissues from experimentally infected chickens by reverse transcription-polymerase chain reaction. Comparison with an immunohistochemical technique

Oligonucleotide pairs were constructed for priming the amplification of fragments of nucleocapsid (N) protein and spike glycoprotein (S) genes of avian infectious bronchitis virus (IBV) by reverse transcriptionpolymerase chain reaction (RT-PCR). One oligonucleotide pair amplified a common segment of the N-gene and could detect various strains of IBV in allantoic fluid from inoculated chicken embryos, and in tracheal tissue preparations from experimentally infected chickens. Four pairs of oligonucleotides selectively primed the amplification of the S1 gene of Massachusetts/Connecticut, D1466, D274/D3896 and 793B strains of IBV, respectively. Groups of specific pathogen free chickens were experimentally inoculated with the Massachusetts (H120, M41), the D1466 and the 793B strains of IBV, and tracheal tissue preparations were made from each bird for RT-PCR and for immunohistochemistry (IHC) up to 3 days post-inoculation. The N-gene RT-PCR detected IBV in 82% of the chickens, while IHC only detected IBV in 60%. This difference was significant (P<0.02). The detection rate by N-gene RT-PCR varied from 67 to 100% for the various strains of IBV inoculated. The S1 gene oligonucleotide pairs were applied to the same tissue preparations and they detected specifically the Massachusetts (M41 and H120), the D1466 and the 793B strains of IBV at rates varying between 58 and 92%. When the mixtures of the primers were applied, the detection rate in tissue preparations was reduced to the level of 50 to 67%. It is concluded that the direct detection of IBV in tracheal tissues by RT-PCR is more sensitive than IHC and that the RT-PCR technique is able to distinguish between types of IBV.

Abstract 1668: Effective targeting of colorectal cancer with a recombinant antibody mixture against EGFR, HER3 and IGF1R

The epidermal growth factor receptor (EGFR) plays an important role in the development and maintenance of the malignant phenotype of several human cancers. Therefore, it is a frequently pursued therapeutic target and several antibodies targeting EGFR have been clinically approved. However, the clinical responses to current anti-EGFR agents are often modest, indicating a need for improved therapeutics. Resistance mechanisms to anti-EGFR antibodies include ligand up-regulation, receptor tyrosine kinase plasticity, and mutations in downstream signaling molecules such as KRAS, BRAF, and PIK3CA.

Here, we present data showing that a mixture of antibodies targeting HER3, EGFR, and IGF1R (HEI mixture) with high affinity ligand-blocking antibodies induced growth inhibition in a large panel of cancer cell lines. Synergies of simultaneous inhibition of the three targets were frequently seen in cell lines and xenograft tumor models. In particular, colorectal cancer cell lines were sensitive to the HEI mixture and superiority to cetuximab was seen in several cell lines. Surprisingly, the HEI mixture was effective at inhibiting the growth of KRAS and BRAF mutated cell lines, suggesting that the three receptor tyrosine kinases may still contribute to the malignant phenotype of tumors with these genomic alterations. Colorectal cancer is thought to be a ligand driven disease and hence the inhibitory activity of the HEI mixture was tested in the presence of EGFR, HER3 and IGF1R ligands and compared with the activity of cetuximab. As expected, the HEI mixture was able to block growth stimulation induced by all ligands, whereas heregulin and IGF1/IGF2 caused resistance to cetuximab.

A clinically relevant subpopulation of colorectal cancer harbors amplification of IGF2, a major ligand for IGF1R, and hence should display sensitivity to IGF1R targeting. The HEI mixture was tested in three metastatic colorectal PDX models with IGF2 overexpression and induced tumor regression in all three models.

In conclusion, our data indicate that simultaneous targeting of EGFR, HER3 and IGFR1 provides a broader efficacy than targeting a single receptor, and thereby provides a rationale for simultaneous targeting of the three receptors with a recombinant antibody mixture.

Citation Format: Christina Egebjerg, Camilla Fröhlich, Karsten Wessel Eriksen, Thomas Tuxen Poulsen, Klaus Kofoed, Thomas Bouquin, Andrea Bretotti, Livio Trusolino, Ivan David Horak, Michael Kragh, Mikkel Wandahl Pedersen. Effective targeting of colorectal cancer with a recombinant antibody mixture against EGFR, HER3 and IGF1R. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1668. doi:10.1158/1538-7445.AM2015-1668

Analysing migrations of Atlantic cod Gadus morhua in the north-east Atlantic Ocean: then, now and the future

The application of data storage tags bears the potential for a quantum leap in the research on fish migrations, because not only first-capture and recapture positions are known, but at least theoretically, the migration path during the period at large can be reconstructed. Position, however, cannot be measured directly but has to be estimated using the available data on light, temperature, pressure and salinity. The reconstructed locations based on advanced estimation techniques have been termed geolocations. Examples are discussed which illustrate the applicability of geolocations in individual path descriptions, separation of reproductively isolated populations, timing and areas of spawning, tidal transport and use of protected areas. The examples are based on archival tag data from the North Sea, the Baltic Sea, the Barents Sea and Faroese and Icelandic Waters. Besides presenting the state-of-the-art geolocations for cod Gadus morhua in the north-east Atlantic Ocean, the major aim of this review is to raise awareness of gaps in knowledge and to identify ideas for new research.

Rational identification of an optimal antibody mixture for targeting the epidermal growth factor receptor

The epidermal growth factor receptor (EGFR) is frequently dysregulated in human malignancies and a validated target for cancer therapy. Two monoclonal anti-EGFR antibodies (cetuximab and panitumumab) are approved for clinical use. However, the percentage of patients responding to treatment is low and many patients experiencing an initial response eventually relapse. Thus, the need for more efficacious treatments remains. Previous studies have reported that mixtures of antibodies targeting multiple distinct epitopes are more effective than single mAbs at inhibiting growth of human cancer cells in vitro and in vivo. The current work describes the rational approach that led to discovery and selection of a novel anti-EGFR antibody mixture Sym004, which is currently in Phase 2 clinical testing. Twenty-four selected anti-EGFR antibodies were systematically tested in dual and triple mixtures for their ability to inhibit cancer cells in vitro and tumor growth in vivo. The results show that targeting EGFR dependent cancer cells with mixtures of antibodies is superior at inhibiting their growth both in vitro and in vivo. In particular, antibody mixtures targeting non-overlapping epitopes on domain III are efficient and indeed Sym004 is composed of two monoclonal antibodies targeting this domain. The superior growth inhibitory activity of mixtures correlated with their ability to induce efficient EGFR degradation.

Sym004: a novel synergistic anti-epidermal growth factor receptor antibody mixture with superior anticancer efficacy

Epidermal growth factor receptor (EGFR) is a validated therapeutic target in cancer and EGFR antagonists with greater effectiveness than existing clinical agents remain of interest. Here, we report a novel approach based on Sym004, a mixture of two anti-EGFR monoclonal antibodies directed against distinct nonoverlapping epitopes in EGFR extracellular domain III. Like anti-EGFR monoclonal antibodies in current clinical use, Sym004 inhibits cancer cell growth and survival by blocking ligand-binding receptor activation and phosphorylation and downstream receptor signaling. However, unlike the other antibodies, Sym004 induces rapid and efficient removal of the receptor from the cancer cell surface by triggering EGFR internalization and degradation. Compared with reference anti-EGFR monoclonal antibodies, Sym004 exhibited more pronounced growth inhibition in vitro and superior efficacy in vivo. Together, these findings illustrate a strategy to target EGFR more effectively than existing clinical antibodies.

Activation of the EGFR gene target EphA2 inhibits epidermal growth factor-induced cancer cell motility

EphA2 overexpression has been reported in many cancers and is believed to play an important role in tumor metastasis and angiogenesis. We show that the activated epidermal growth factor receptor (EGFR) and the cancer-specific constitutively active EGFR type III deletion mutant (EGFRvIII) induce the expression of EphA2 in mammalian cell lines, including the human cancer cell lines A431 and HN5. The regulation is partially dependent on downstream activation of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase and is a direct effect on the EphA2 promoter. Furthermore, EGFR and EphA2 both localize to the plasma membrane and EphA2 coimmunoprecipitates with activated EGFR and EGFRvIII. Ligand activation of EphA2 and EphA2 knockdown by small interfering RNA inhibit EGF-induced cell motility of EGFR-overexpressing human cancer cells, indicating a functional role of EphA2 in EGFR-expressing cancer cells.

[Mutations in the epidermal growth factor receptor: structure and biological function in human tumors]

The epidermal growth factor receptor (EGFR) plays an important role in the regulation of normal cell proliferation, differentiation and survival. For this reason EGFR status is often altered in a range of human tumor types and generally correlates with a poor prognosis. In recent years a number of mutations in the EGFR gene have been noted that lead to the expression of overactive or constitutively active aberrant receptors. These receptors have been shown to participate actively in the process of tumor genesis. This review provides an overview of the structure of these mutations and their biological function in human tumors plus the potentials of anticancer therapy.

Differential response to gefitinib of cells expressing normal EGFR and the mutant EGFRvIII

Epidermal growth factor receptor (EGFR) is frequently amplified and/or mutated in a number of human tumours and abnormal signalling from this receptor is believed to contribute to the malignant phenotype seen in these tumours. Gefitinib is a small molecule inhibitor that specifically binds and inhibits the EGFR tyrosine kinase and has been shown to inhibit the growth, proliferation, survival and invasion of a range of tumour cells overexpressing EGFR. However, clinical response to gefitinib has failed to correlate with EGFR levels and activity, indicating that other molecular mechanisms such as downstream signalling and mutations could be of importance in predicting clinical response. We therefore investigated the effect of the specific EGFR inhibitor gefitinib on the phosphorylation level, signalling and growth of cells expressing the naturally occurring constitutively active EGFR variant EGFRvIII, a low nontransforming level of EGFR and a high transforming level of EGFR. Results show that levels of gefitinib sufficient to suppress EGFR phosphorylations, EGFR-mediated proliferation and EGFR-mediated anchorage-independent growth are not sufficient to inhibit these features in cells expressing EGFRvIII. Furthermore, the data indicate that long-term exposure of EGFRvIII-expressing cells to low concentrations of gefitinib (0.01–0.1 μM) result in increased phosphotyrosine load of the receptor, increased signalling to ERK and stimulation of proliferation and anchorage-independent growth, presumably by inducing EGFRvIII dimerisation. Higher concentrations of gefitinib (1–2 μM), on the other hand, significantly decreased EGFRvIII phosphotyrosine load, EGFRvIII-mediated proliferation and anchorage-independent growth. Further studies are needed to investigate the implications of these important findings in the clinical setting.

The insulinoma-associated 1: a novel promoter for targeted cancer gene therapy for small-cell lung cancer

The insulinoma-associated 1 (INSM1) gene is expressed exclusively during early embryonal development, but has been found re-expressed at high levels in neuroendocrine tumors. The regulatory region of the INSM1 gene is therefore a potential candidate for regulating expression of a therapeutic gene in transcriptionally targeted cancer gene therapy against neuroendocrine tumors. We analyzed expression of a reporter gene from a 1.7 kb region of the INSM1 promoter in a large number of small-cell lung cancer (SCLC) cell lines. This INSM1 promoter region showed very high levels of expression in most of the SCLC cell lines and expression was absent in cell lines of non-neuroendocrine origin. Inclusion of the general transcriptional enhancer from SV40 compromised the specificity of the promoter and did not enhance transcription in most of the SCLC cell lines. For comparison, the region of the gastrin releasing peptide (GRP) previously suggested for SCLC gene therapy was analyzed in a similar manner. High expression was observed for a number of cell lines, but unlike for the INSM1 promoter, reporter gene expression from the GRP promoter did not correlate to the relative GRP mRNA levels, demonstrating that this region may not contain all necessary regulatory elements. Expression of the suicide gene herpes simplex virus thymidine kinase (HSV-TK) from the INSM1 promoter in combination with treatment with the prodrug ganciclovir (GCV) caused a significant increase in GCV sensitivity specifically in INSM1-expressing cell lines. The INSM1 promoter is therefore a potential novel tool for transcriptionally targeted gene therapy for neuroendocrine tumors.

Epidermal growth factor receptor mutation type III transfected into a small cell lung cancer cell line is predominantly localized at the cell surface and enhances the malignant phenotype

In the present study we transfected the epidermal growth factor receptor (EGFR)-negative small cell lung cancer cell line, GLC3, with the type III EGFR mutation (EGFRvIII). The EGFRvIII protein could be detected by Western blot analysis as a 145-kDa protein, which by immunohistochemistry appeared to be localized at the cell surface. Ultrastructurally EGFRvIII was expressed mainly at the cell surface with clusters at cell-cell contacts. In the in vitro invasion assay, GLC3-EGFRvIII cells had a approximately 5-fold increased invasion compared with uninduced GLC3-EGFRvIII, GLC3-Tet-On and the parental cell line. GLC3-Tet-On appeared uniform in size with adherence junctions at cell-cell contacts. In uninduced GLC3-EGFRvIII cells adherence junctions were also present but less distinct. In doxycycline-pretreated GLC3-EGFRvIII cells, adherence junctions were absent. We conclude that the expression of EGFRvIII results in a more malignant phenotype. This effect appears to involve the disruption of adherence junctions.

Profile of differentially expressed genes mediated by the type III epidermal growth factor receptor mutation expressed in a small-cell lung cancer cell line

Previous studies have shown a correlation between expression of the EGF receptor type III mutation (EGFRvIII) and a more malignant phenotype of various cancers including: non-small-cell lung cancer, glioblastoma multiforme, prostate cancer and breast cancer. Thus, a detailed molecular genetic understanding of how the EGFRvIII contributes to the malignant phenotype is of major importance for future therapy. The GeneChip Hu6800Set developed by Affymetrix was used to identify changes in gene expression caused by the expression of EGFRvIII. The cell line selected for the study was an EGF receptor negative small-cell-lung cancer cell line, GLC3, stably transfected with the EGFRvIII gene in a Tet-On system. By comparison of mRNA levels in EGFRvIII-GLC3 with those of Tet-On-GLC3, it was found that the levels of mRNAs encoding several transcription factors (ATF-3, JunD, and c-Myb), cell adhesion molecules (CD36, CD24), signal transduction related molecules (MKP-1) and other molecules related to cancer (CD98, thymosin beta-10) were altered in the EGFRvIII transfected cell line. Northern hybridisations and Western blot analyses were used to verify selected results. The results indicate that expression of EGFRvIII alters expression of genes involved in the control of cell growth, survival and motility.

The type III epidermal growth factor receptor mutation. Biological significance and potential target for anti-cancer therapy

Mutations in the epidermal growth factor receptor occur frequently in a number of human tumours including gliomas, non-small-cell lung carcinomas, ovarian carcinomas and prostate carcinomas. The type III epidermal growth factor receptor mutation (variously named EGFRvIII, de2-7 EGFR or AEGFR), which lacks a portion of the extracellular ligand binding domain, is the most common. Here, we review the current status with regard to the role of EGFRvIII in human cancers. A detailed discussion of the formation of EGFRvIII and its structure at the protein level are likewise included along with a discussion of its more functional roles. The design and use (preclinical and clinical) of small molecule inhibitors, antibodies, and antisense oligonucleotides against wild-type EGFR are considered in detail as these strategies can be directly adapted to target EGFRvIII. Finally, the status of EGFRvIII targeted therapy is reviewed.

Coregulation of glucose uptake and vascular endothelial growth factor (VEGF) in two small-cell lung cancer (SCLC) sublines in vivo and in vitro

We examined the relationship between (18)F- labeled 2-fluro-2-deoxy-d-glucose (FDG) uptake, and expression of glucose transporters (GLUTs) in two human small-cell lung cancer (SCLC) lines CPH 54A and CPH 54B. Changes in the expression of GLUTs and vascular endothelial growth factor (VEGF) during 12-, 18-, and 24 hours of severe hypoxia in vivo (xenografts) and in vitro (cell cultures) were recorded for both tumor lines. The two SCLC lines are subpopulations of the same patient tumor. In spite of their common genomic origin they represent consistently different metabolic and microenvironmental phenotypes as well as treatment sensitivities. There were higher levels of Glut-1 protein in 54B and a correspondingly higher FDG uptake in this tumor line (P<.001). During hypoxia a significant upregulation of in VEGF mRNA, GLUT-1 mRNA, and Glut-1 and -3 protein occurred with a distinctly different time course in the two cell lines. A similar co-upregulation of GLUT and VEGF was seen in hypoxic tumors of both lines. There were no significant changes of HIF-1alpha mRNA during hypoxia in either of the cell lines. A more detailed understanding of such correlations between glucose metabolism, angiogenesis, and microenvironmental phenotype of tumors, by positron emission tomography (PET) and molecular techniques might further sophisticate our interpretation of glycolytic predominance in tumors as seen by 18FFDG PET.

Relationship between vessel density and expression of vascular endothelial growth factor and basic fibroblast growth factor in small cell lung cancer in vivo and in vitro

In 21 human small cell lung cancer (SCLC) cell lines, we determined the expression of mRNA and secreted protein levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). The VEGF expression was highly variable between cell lines, with a > 100-fold variation, under identical in vitro conditions. The bFGF expression in cell lines was generally very low. Nine of the cell lines were further analyzed during growth as solid tumor xenografts in nude mice (in vivo). A more uniform VEGF protein expression was present in vivo. Compared with the variable in vitro expression, VEGF was relatively up-regulated in the tumor lines CPH 54A and CPH 54B and down-regulated in GLC 3. One line, DMS 79, had a high VEGF expression in vivo as well as in vitro. The vessel density was determined by Chalkley point counting on CD31 immunostained cryosections of tumors of each of the nine SCLC lines. We found a strong positive correlation between vessel density and tissue VEGF protein expression (r(s) = 0.75; P = 0.02) and a comparatively strong negative correlation (r(s) = -0.80; P = 0.01) between vessel density and tissue bFGF expression. No significant correlation was present between vessel density and in vitro VEGF expression. We conclude that VEGF and bFGF expression is dependent on microenvironmental conditions, as well as cell line-specific factors, and that a strong positive correlation exists between in vivo VEGF expression and vessel density, whereas high tissue levels of bFGF are not correlated with higher vessel densities in SCLC xenografts.

The effect of whisky and wine consumption on total phenol content and antioxidant capacity of plasma from healthy volunteers

OBJECTIVE

To assess whether consumption of 100 ml of whisky or red wine by healthy male subjects increased plasma total phenol content and antioxidant capacity.

DESIGN

A Latin square arrangement to eliminate ordering effects whereby, after an overnight fast, nine volunteers consumed 100 ml of red wine, malt whisky or unmatured 'new make' spirit. Each volunteer participated on three occasions one week apart, consuming one of the beverages each time. Blood samples were obtained from the anticubital vein at intervals up to 4h after consumption of the beverages when a urine sample was also obtained.

RESULTS

Within 30 min of consumption of the wine and whisky, there was a similar and significant increase in plasma total phenol content and antioxidant capacity as determined by the ferric reducing capacity of plasma (FRAP). No changes were observed following consumption of 'new make' spirit.

CONCLUSIONS

Consumption of phenolic-containing alcoholic beverages transiently raises total phenol concentration and enhances the antioxidant capacity of plasma. This is compatible with suggestions that moderate alcohol usage and increased antioxidant intake decrease the risk of coronary heart disease.

Mycoplasma hyopneumoniae infection in pigs: duration of the disease and evaluation of four diagnostic assays

200 SPF pigs were infected by aerosol with Mycoplasma hyopneumoniae and the development of clinical signs, serological and pathological reactions were studied. Mean time to onset of coughing was 13 days. A mean delay of 9 days was observed from onset of coughing until seroconversion against M. hyopneumoniae as measured by ELISA. At an individual level, the sensitivity for this ELISA was estimated to 98-100% and the specificity to 93-100%. Pasteurella multocida was isolated from the majority of the lungs 4 weeks post inoculation with M. hyopneumoniae and the lung lesions in pigs were significantly larger when P. multocida was present as compared to pigs with M. hyopneumoniae alone. An evaluation of cultivation, immunofluorescence, ELISA and polymerase chain reaction for demonstration of M. hyopneumoniae in lungs showed that all four methods have a high sensitivity in the acute stages of pneumonia. In the later stages the sensitivity of cultivation was superior to the other methods. No differences in specificity were observed between the methods. The antigen-ELISA OD values and the immunofluorescence scores revealed a strong positive correlation. Nasal swabs were additionally used for demonstration of M. hyopneumoniae and the polymerase chain reaction was found superior to the other methods.