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Supplementary Data File 2 from Dimethylfumarate Impairs Melanoma Growth and Metastasis

Dimethylfumarate (DMF) inhibits signals transmitted by Rel proteins and is used for the treatment of inflammatory skin diseases such as psoriasis, but potential effects of DMF on tumor progression have yet not been analyzed. We show that DMF reduced melanoma growth and metastasis in severe combined immunodeficient mouse models. To identify targets of DMF action, we analyzed mRNA expression in DMF-treated melanomas by gene chip arrays. Using BiblioSphere software for data analysis, significantly regulated genes were mapped to Gene Ontology terms cell death, cell growth, and cell cycle. Indeed, we found that DMF inhibited proliferation of human melanoma cells A375 and M24met in vitro. The cell cycle was arrested at the G2-M boundary. Moreover, DMF was proapoptotic, as shown by cell cycle analysis and by Annexin V and Apo2.7 staining. These results were confirmed in vivo. DMF reduced proliferation rates of tumor cells as assessed by Ki-67 immunostaining and increased apoptosis as assessed by terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling staining. In conclusion, DMF is antiproliferative and proapoptotic and reduces melanoma growth and metastasis in animal models. (Cancer Res 2006; 66(24): 11888-96)

Supplementary Data File 1 from Dimethylfumarate Impairs Melanoma Growth and Metastasis

Supplementary Figure 1 from Dimethylfumarate Impairs Melanoma Growth and Metastasis

Canine oral malignant melanoma (COMM) is a potentially lethal cancer disease. We established primary cell lines from mostly amelanotic primary COMM and metastases and assessed lesions and derived cells for Melan A, PNL2 and CD146 expression. Then, migration and invasion of CD146-enriched vs -depleted COMM cells were analysed. Epithelial-to-mesenchymal transition (EMT) was addressed by Vimentin-staining and MMP2/MMP9 zymography. Phagocytic behaviour was analysed by histopathological examination and phagocytosis assay. While Melan A- and PNL2-staining yielded inconsistent data, 100% of COMM sections and primary cells showed CD146 expression, suggesting that this protein may serve as a prognostic marker. An overall correlation between CD146-expression and migration/invasion was not observed. All primary cell lines consistently expressed Vimentin and secreted biologically active MMP2, indicating that they had undergone EMT. Importantly, COMM sections exhibited cell-in-cell structures, and all primary cell lines exhibited phagocytic activity, supporting the concept that cell cannibalism may have a role in COMM progression.

Simple Summary Human gastrointestinal lymphomas are rare diseases with an incidence of one per 1,000,000 inhabitants per year. This paucity poses a major challenge in unravelling their underlying mechanism. In comparison, lymphoma is the most common malignancy in domestic cats and the gastrointestinal (GI) tract is the most common location for this disease. Here, we identify the driver mutation STAT5BN642H in feline alimentary lymphoma, thereby establishing felines as a potential new model for a rare and incurable human T cell disease. Abstract Alimentary lymphomas arising from T cells are rare and aggressive malignancies in humans. In comparison, they represent the most common anatomical form of lymphoma in cats. Due to the low prevalence in humans, the underlying pathomechanism for these diseases is poorly characterised, limiting experimental analysis and therapeutic exploration. To date, activating mutations of the JAK/STAT core cancer pathway and particularly the STAT5B oncoprotein have been identified in human enteropathy-associated T cell lymphoma. Here, we describe a high homology of human and feline STAT3 and STAT5B proteins and strong conservation at the genomic level. Analysis of 42 samples of feline T cell alimentary lymphoma reveals broad activation of STAT3 and STAT5B. Screening for known activating mutations in STAT3 or STAT5B identifies the presence of the STAT5BN642H driver mutation in feline enteropathy-associated T cell lymphoma in 7 out of 42 (16.67%) samples in total. Regarding lymphoma subtypes, the majority of mutations with 5 out of 17 (29.41%) cases were found in feline enteropathy-associated lymphoma type II (EATL II). This identification of an oncogenic STAT5B driver mutation in felines recapitulates the genetic situation in the corresponding human disease, thereby establishing the cat as a potential new model for a rare and incurable human T cell disease.

Background There is a large body of evidence supporting bovine papillomavirus types 1 and 2 (BPV1; BPV2) as aetiological agents of equine sarcoids. However, there is conflicting data regarding BPV1/2 infection in sarcoid-free equids. Objectives Data obtained between 2007 and 2017 by BPV1/2 screening of sarcoids and nonsarcoid tumours vs. samples from healthy equids are presented to help clarify this issue. Study design Cross-sectional study. Methods Tumour material obtained from horses, donkeys and mules with confirmed sarcoids (n = 130), suspected sarcoids (n = 120), or nonsarcoid lesions (n = 70), skin biopsies from 102 tumour-free horses and dandruff/hair roots from 35 tumour-free donkeys and mules were screened for BPV1/2 infection. Sample DNA was extracted and validated by equine β-actin PCR. BPV1/2 screening was performed by BPV1/2 E5-specific PCR allowing for the detection of less than 10 viral DNA molecules. Twenty-six amplicons were bidirectionally sequenced and compared to known E5 variants using BLAST program. Results BPV1/2 E5 PCR scored positive for 130/130 diagnosed sarcoids, 63/120 suspected sarcoids and 13/70 nonsarcoid lesions, whereas 137/137 DNA aliquots derived from tumour-free equids tested negative. On predicted E5 protein level, six different BPV1 E5 variants were identified. Main limitations The diagnosis of equine sarcoid was not confirmed in 120 lesions. Conclusions Lack of BPV1/2 E5 DNA in tumour-free equids and the prevalence of sarcoid disease in young adult individuals suggest that the time span between initial infection and sarcoid development is short. This contrasts with the long phase of virus latency characterising infection of humans by carcinogenic papillomaviruses. Presence of BPV1/2 DNA in several cases of poor wound healing/hypergranulation and dermatitis points to these skin disorders being possibly co-induced by BPV1/2. PCR screening of tumour tissue/scrapings for BPV1/2 DNA represents a reliable tool for the rapid validation of a clinical diagnosis of equine sarcoid.

The use of transgenic mouse models has revolutionized the study of many human diseases. However, murine models are limited in their representation of spontaneously arising tumors and often lack key clinical signs and pathological changes. Thus, a closer representation of complex human diseases is of high therapeutic relevance. Given the high failure rate of drugs at the clinical trial phase (i.e., around 90%), there is a critical need for additional clinically relevant animal models. Companion animals like cats and dogs display chronic inflammatory or neoplastic diseases that closely resemble the human counterpart. Cat and dog patients can also be treated with clinically approved inhibitors or, if ethics and drug safety studies allow, pilot studies can be conducted using, e.g., inhibitors of the evolutionary conserved JAK-STAT pathway. The incidence by which different types of cancers occur in companion animals as well as mechanisms of disease are unique between humans and companion animals, where one can learn from each other. Taking advantage of this situation, existing inhibitors of known oncogenic STAT3/5 or JAK kinase signaling pathways can be studied in the context of rare human diseases, benefitting both, the development of drugs for human use and their application in veterinary medicine.

Bovine papillomavirus types 1 and 2 (BPV-1 and BPV-2) are known to induce common equine skin tumours, termed sarcoids. Recently, it was demonstrated that vaccination with BPV-1 virus-like particles (VLPs) is safe and highly immunogenic in horses. To establish a BPV-1 challenge model for evaluation of the protective potential of BPV-1 VLPs, four foals were injected intradermally with infectious BPV-1 virions and with viral genome-based and control inocula, and monitored daily for tumour development. Blood was taken before inoculation and at weekly intervals. BPV-1-specific serum antibodies were detected by a pseudo-virion neutralization assay. Total nucleic acids extracted from tumours, intact skin and PBMCs were tested for the presence of BPV-1 DNA and mRNA using PCR and RT-PCR, respectively. Intralesional E5 oncoprotein expression was determined by immunofluorescence. Pseudo-sarcoids developed exclusively at sites inoculated with virions. Tumours became palpable 11–32 days after virion challenge, reached a size of ≤20 mm in diameter and then resolved in ≤6 months. No neutralizing anti-BPV-1 serum antibodies were detectable pre- or post-challenge. BPV-1 DNA was present in lesions but not in intact skin. In PBMCs, viral DNA was already detectable before lesions were first palpable, in concentrations correlating directly with tumour growth kinetics. PBMCs from two of two foals also harboured E5 mRNA. Immunofluorescence revealed the presence of the E5 protein in tumour fibroblasts, but not in the apparently normal epidermis overlying the lesions. Together with previous findings obtained in horses and cows, these data suggest that papillomavirus infection may include a viraemic phase.

Summary Background Inhibition of mTOR complex 1 (mTORC1) with rapamycin leads to phosphorylation of AKT in some cancer cells, with unknown biological consequences. The role of this phosphorylation in melanoma is unknown, although preliminary clinical data indicate poor activity of rapalogues in melanoma. Objectives We aimed at elucidating the role of AKT phosphorylation after mTORC1 inhibition in melanoma cells. Methods Western blotting, apoptosis assays, cell cycle analyses and viability assays were performed to analyse the effects of rapamycin and LY294002 treatment on melanoma cells. For suppression of mTOR complex 2 (mTORC2) an siRNA directed against rictor was used. Results Rapamycin showed limited effects on cell viability but resulted in strong and lasting AKT phosphorylation in melanoma cells. Combined PI3K/mTOR inhibition with LY294002 had pronounced effects on viability but also led to increased AKT phosphorylation after prolonged treatment. In contrast, combination of rapamycin plus LY294002 suppressed AKT phosphorylation. Suppression of AKT phosphorylation did not correlate with decreases in cell viability. Inhibition of mTORC2 led to reduced levels of phosphorylated AKT. Conclusions mTORC1 inhibition with rapamycin and with LY294002 can lead to AKT phosphorylation in melanoma cells via mTORC2. Combination of rapamycin and LY294002 suppresses AKT phosphorylation but without significant effect on treatment efficacy.

Cellular differentiation and programmed cell death are tightly controlled to maintain tissue homeostasis and proper organ function. In a screen for apoptosis specific gene products, we isolated an immediate early apoptosis response gene from myelomonocytic stem cells that appears to play a key regulatory role in a number of cell types and may be of particular importance in cells of the central nervous system. The gene's 28 kDa protein product interacts with the C-terminal ectodomain of the Na + /K + -ATPase (NKA) β 1 subunit and was therefore named NKIP (NKA Interacting Protein). NKIP is coexpressed with NKA, localizes to lysosomes and the endoplasmic reticulum and is predominantly expressed in excitable tissues including polarized epithelia and the central nervous system. NKIP has been characterized as an endogenous suppressor of the NKA as reduction of NKIP in PC12 cells significantly increases NKA activity. In pluripotent NT2 progenitor cells, NKIP induced rapidly K + -level-dependent cell death. NKIP overexpression induced growth factor-independent neurite outgrowth, which was associated with MEK-independent phosphorylation of the transcription factor ERK1/2. Thus, we have identified NKIP as an important novel protein that interacts to the NKA complex, influencing cellular ion balance, induction of apoptosis and neuronal differentiation.

The antiapoptotic protein Bcl-2 contributes to a more chemoresistant phenotype of nonsmall cell lung cancer and therefore serves as an important target for novel anticancer strategies. Interestingly, docetaxel as a standard of care for treatment of nonsmall cell lung cancer has been shown to inactivate the Bcl-2 function by phosphorylation. We investigated the Bcl-2 expression status of nonsmall cell lung cancer cells in response to cisplatin or docetaxel and its effect on sensitizing nonsmall cell lung cancer cells by Bcl-2 downregulation employing a small interfering RNA approach. Bcl-2 expression was assessed by Western blotting and RT-PCR. Cell proliferation and apoptosis of nonsmall cell lung cancer cells were measured by an MTS-based assay and Annexin V/7-Aminoactinomycin, respectively. Combination treatment of Bcl-2 small interfering RNA with cisplatin resulted in a synergistic activity. By contrast, Bcl-2 downregulation did not sensitize nonsmall cell lung cancer cells to docetaxel. Of note, docetaxel treatment resulted in Bcl-2 phosphorylation of nonsmall cell lung cancer cells, whereas cisplatin increased the Bcl-2 overall expression and abrogated Bcl-2 phosphorylation. On the basis of our findings, a Bcl-2 silencing approach appears to be a suitable strategy for sensitizing nonsmall cell lung cancer to cisplatin, but not to docetaxel.

Cell-free circulating tumor DNA in the plasma of cancer patients has become a common point of interest as indicator of therapy options and treatment response in clinical cancer research. Especially patient- and tumor-specific single nucleotide variants that accurately distinguish tumor DNA from wild type DNA are promising targets. The reliable detection and quantification of these single-base DNA variants is technically challenging. Currently, a variety of techniques is applied, with no apparent “gold standard”. Here we present a novel qPCR protocol that meets the conditions of extreme sensitivity and specificity that are required for detection and quantification of tumor DNA. By consecutive application of two polymerases, one of them designed for extreme base-specificity, the method reaches unprecedented sensitivity and specificity. Three qPCR assays were tested with spike-in experiments, specific for point mutations BRAF V600E, PTEN T167A and NRAS Q61L of melanoma cell lines. It was possible to detect down to one copy of tumor DNA per reaction (Poisson distribution), at a background of up to 200 000 wild type DNAs. To prove its clinical applicability, the method was successfully tested on a small cohort of BRAF V600E positive melanoma patients.

Dimethylfumarate (DMF) inhibits signals transmitted by Rel proteins and is used for the treatment of inflammatory skin diseases such as psoriasis, but potential effects of DMF on tumor progression have yet not been analyzed. We show that DMF reduced melanoma growth and metastasis in severe combined immunodeficient mouse models. To identify targets of DMF action, we analyzed mRNA expression in DMF-treated melanomas by gene chip arrays. Using BiblioSphere software for data analysis, significantly regulated genes were mapped to Gene Ontology terms cell death, cell growth, and cell cycle. Indeed, we found that DMF inhibited proliferation of human melanoma cells A375 and M24met in vitro. The cell cycle was arrested at the G2-M boundary. Moreover, DMF was proapoptotic, as shown by cell cycle analysis and by Annexin V and Apo2.7 staining. These results were confirmed in vivo. DMF reduced proliferation rates of tumor cells as assessed by Ki-67 immunostaining and increased apoptosis as assessed by terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling staining. In conclusion, DMF is antiproliferative and proapoptotic and reduces melanoma growth and metastasis in animal models. (Cancer Res 2006; 66(24): 11888-96)

Two novel interleukin-24 (IL-24) splice variants were identified in normal human melanocytes by sequencing cloned polymerase chain reaction (PCR) products that are not expressed in metastatic melanoma. These gene products have been generated by differential skipping of exons 3 (IL-24 delE3) and 5 (IL-24 delE5). IL-24 delE3 has limited sequence identity to the IL-24-interacting protein mda-7s, and IL-24 delE5 is homologous to IL-24.

Melanoma is one of the most aggressive neoplastic transformations and characterized by a high metastatic potential. The current study was performed to assess the impact of “spleen tyrosine kinase” (Syk), a non-receptor-associated tyrosine kinase, on growth and metastatic behavior of melanoma cells in vitro and in a severe combined immunodeficient (SCID)-mouse/human-melanoma xenotransplantation model in vivo. Syk was expressed in melanocytes but was found to be downregulated in melanoma cells. Vector-driven expression of Syk in two different melanoma cell lines did not influence growth speed, but significantly reduced the invasive growth potential of both cell lines in a Matrigel assay in vitro. In a SCID-mouse/human melanoma xenotransplantation model, Syk expressing Mel-Juso cells exhibited delayed and reduced tumor growth. After intravenous as well as subcutaneous injection of tumor cells, Syk-transfected cells formed significantly fewer metastatic tumor lesions than control cells. The presented data define Syk as a novel regulator of metastatic behavior of melanoma cells.

Expression of melanoma differentiation associated gene-7 (mda-7) also known as interleukin 24 (IL-24) decreases during melanoma cell differentiation and induces apoptosis in melanoma cells but not in melanocytes. Here we identify a novel splice variant of the cancer growth suppressor gene mda-7/IL-24 (mda-7s) that is differentially expressed in RNA preparations from normal human melanocytes, transformed melanocytes, nevi, subcutaneous metastasis, lymph node metastasis, and melanoma cell lines. The 450 bp mda-7s mRNA encodes a protein of 63 residues with a molecular weight of 12 kDa. mda-7s lacks exons 3 and 5 of the full-length transcript and contains only 14 amino acids of homology to MDA-7 located within the signal peptide region of the wild-type sequence. Despite minimal homology, MDA-7S coprecipitates full length MDA-7 and reduces secretion of cotransfected MDA-7. mda-7 and mda-7s are coexpressed in all RNA preparations other than subcutaneous and lymph node metastasis where mda-7s expression is lacking. mda-7s expression is therefore linked to a non-metastatic phenotype.

Background: The selective D2 antagonist tiapride is administered in various movement disorders. Furthermore, there are indications that tiapride increases platelet counts. Aim: To characterize tiapride's potential to increase platelet counts in healthy subjects and patients with movement disorders. Methods: In Part A, 10 healthy volunteers received tiapride (300 mg/day) for 21 days in a longitudinal, prospective, open trial. One hundred healthy subjects served as controls. Part B was a retrospective analysis of 15 patients with movement disorders on tiapride [Huntington's disease (n=6), Morbus Little (n=3), hyperkinetic syndromes of undetermined etiology (n=3), blepharospasm (n=1), cervical dystonia (n=1), perioral dyskinesia (n=1)] and 15 age- and sex-matched controls. Results: Part A: Although serum prolactin levels increased by 526±14%, confirming good drug compliance, tiapride elicited only minor changes in platelet counts. Part B: Platelet counts correlated positively with the dose of tiapride (100–800 mg/day; r=.67; P=.007). Platelet counts were significantly higher in patients on tiapride compared to healthy age-matched controls (P

Inhibition of mTOR complex 1 (mTORC1) with rapamycin leads to phosphorylation of AKT in some cancer cells with unknown biological consequences. A mechanism involving insulin receptor substrate (IRS) and phosphatidylinositol 3-kinase (PI3K) leading to increased AKT phosphorylation has been described. For melanoma, it is unknown, whether this feedback loop plays a role, although preliminary clinical data indicate poor activity of rapalogues in melanoma. Here, we report that treatment of melanoma cells with rapamycin resulted in strong and long lasting AKT phosphorylation, but had little or no effects on cell viability, cell cycle arrest or apoptosis. Combined PI3K/mTOR inhibition with LY294002 had strong effects on these parameters, but also led to increased phospho-AKT levels after prolonged treatment. In contrast to the single treatments, combination of rapamycin plus LY294002 was able to suppress AKT phosphorylation even after prolonged treatment. Inhibition of mTOR complex 2 (mTORC2) using RNAi led to reduced levels of p-AKT, also under conditions when mTORC1 was inhibited. PTEN mutant melanoma cells showed slightly increased levels of AKT phosphorylation compared to PTEN wild-type cells. Thus, our results indicate that mTORC1 inhibition with specific inhibitors such as rapamycin as well as with multi-target inhibitors such as LY294002 can lead to AKT phosphorylation in melanoma cells via mTORC2, but without significant influence on treatment efficacy in vitro. from 13th Scientific Symposium of the Austrian Pharmacological Society (APHAR). Joint Meeting with the Austrian Society of Toxicology (ASTOX) and the Hungarian Society for Experimental and Clinical Pharmacology (MFT) Vienna, Austria. 22–24 November 2007

This study compares the antineoplastic potential of a novel treatment strategy combining cell cycle inhibitor-779 (CCI-779) plus dacarbazine (DTIC) versus DTIC monotreatment, the current chemotherapeutic mainstay in combating metastatic melanoma. A controlled four-group parallel study design comprising 24-40 mice per tumor cell line was used in a severe combined immunodeficiency (SCID)-mouse xenotransplantation model. SCID mice were injected with 518A2, Mel-JUSO, or 607B human melanoma cells. After they developed tumors, mice received daily CCI-779 or solvent over 14 days. From treatment day 4-8 mice were additionally injected with DTIC or saline. Treatment with CCI-779 plus DTIC was superior to single agent DTIC in two out of three cell lines (P0.05). The tumor weight reduction was 44+/-17 and 61+/-6% compared with DTIC monotreatment in Mel-JUSO and 607B melanomas, respectively (P0.05). In contrast, in 518A2 xenotransplants, CCI-779 plus DTIC treatment was as effective as DTIC monotreatment. CCI-779 monotherapy exerted no statistically significant antitumor effect. Collectively, these data indicate that CCI-779 has the potential to increase the chemotherapeutic efficacy, as the combination of CCI-779 plus DTIC proved to be more efficacious compared to DTIC monotherapy in two out of three melanoma cell lines in vivo.

Background: This study set out to investigate the antitumor effects of a treatment strategy combining the mTOR inhibitor CCI-779 with cisplatin in vitro and in a human melanoma SCID mouse model. Methods: In vitro 518A2, Mel-JUSO or 607B cell lines were incubated with CCI-779, cisplatin and CCI-779 plus cisplatin. Based on these results, a 4-group, parallel, controlled experimental study design was initiated in vivo. SCID mice were injected with melanoma cells, and after the development of tumors the mice received daily injections of CCI-779 or solvent. On treatment days 2 and 6 cisplatin or mock solution were administered. Results: In vitro a synergistic antitumor effect was observed for the treatment regimen of CCI-779 plus cisplatin. In SCID mice after 2 weeks of therapy with CCI-779 plus cisplatin 4 of 6 tumors of the 518A2 cell line were completely eradicated. In the two remaining 518A2 xenografts this treatment strategy reduced the tumor weight by 94 ± 9% compared to solvent. CCI-779 plus cisplatin also exerted a significant antitumor effect in Mel-JUSO and 607B xenografts compared to mock-treated animals. Conclusion: We provide circumstantial evidence that the use of CCI-779 plus cisplatin might qualify as a promising strategy in the treatment of human melanoma.

Stem cell factor (SCF) stimulation of the receptor tyrosine kinase c-kit has effects on the proliferation, differentiation, and apoptotic regulation of hematopoietic progenitor cell populations. Rat bone marrow myelomonocytic stem cells (MSC) isolated in vitro by wheat germ agglutinin culture exclusively undergo self-renewal divisions when stimulated by SCF but bipotentially differentiate in the presence of dexamethasone or 1alpha,25-dihydroxyvitamin D(3) to granulocytes and macrophages, respectively. We show here that withdrawal of SCF from MSC induces rapid apoptosis in all stages of the cell cycle accompanied by development of an ultrastructural apoptotic morphology. To investigate immediate-early gene induction during MSC apoptosis, a differential display polymerase chain reaction (DD-PCR) screen coupled with rapid amplification of cDNA ends (RACE) PCR was performed. An immediate-early apoptosis response gene was isolated from growth factor-deprived MSC that was not expressed during self-renewal or differentiation induction cultures containing SCF. The protein contains a PEST region enriched in proline, glutamic acid, serine, and threonine residues common to proteins with a high turnover and has a cytoplasmic, vesicular localization in apoptotic MSC shown by immunohistochemistry. The human orthologous gene, isolated by RACE PCR, shows 86% homology to the rat protein and high similarity with a human uncharacterized hypothalamus predicted protein (HSMNP1) localized to the long arm of chromosome 20. Because deletions in this region are a common occurrence in a wide range of myeloproliferative disorders characterized by treatment resistance to apoptosis, HSMNP1 expression may play a role in normal and pathological myeloid development.

Expression of melanoma differentiation associated gene-7 (mda-7) also known as interleukin 24 (IL-24) decreases during melanoma cell differentiation and induces apoptosis in melanoma cells but not in melanocytes. Here we identify a novel splice variant of the cancer growth suppressor gene mda-7/IL-24 (mda-7s) that is differentially expressed in RNA preparations from normal human melanocytes, transformed melanocytes, nevi, subcutaneous metastasis, lymph node metastasis, and melanoma cell lines. The 450 bp mda-7s mRNA encodes a protein of 63 residues with a molecular weight of 12 kDa. mda-7s lacks exons 3 and 5 of the full-length transcript and contains only 14 amino acids of homology to MDA-7 located within the signal peptide region of the wild-type sequence. Despite minimal homology, MDA-7S coprecipitates full length MDA-7 and reduces secretion of cotransfected MDA-7. mda-7 and mda-7s are coexpressed in all RNA preparations other than subcutaneous and lymph node metastasis where mda-7s expression is lacking. mda-7s expression is therefore linked to a non-metastatic phenotype.

The β2-adrenergic receptor (ADRB2) is a GTP-binding-protein-coupled receptor produced by a wide variety of cell types. Stimulation of ADRB2 by catecholamines or synthetic therapeutic agonists promotes physiologic processes as varied as smooth muscle relaxation and lipolysis. Stimulation of ADRB2 is characterized by rapid desensitization governed by receptor internalization, which plays a direct role in the response to catecholamines and synthetic agonists governing cellular responses (1). ADRB2 is transcribed from an intronless gene on chromosome 5q32 that encodes a 413-residue protein with 7 transmembrane domains (2). Within the ADRB2 gene, 13 single-nucleotide polymorphisms (SNPs) have been identified (3), including 3 coding ADRB2 missense polymorphisms that alter protein function (4). A threonine-to-isoleucine (T164I) substitution in the fourth transmembrane domain alters ligand binding and decreases adenylate cyclase activation but is rare in the population (5). The extracellular domain N-terminal arginine-to-glycine (R16G) and glutamine-to-glutamic acid (Q27E) polymorphisms are common and widely distributed within the population. These polymorphisms strongly influence the degree of agonist-mediated receptor down-regulation. Whereas Q27E induces complete resistance to down-regulation in combination with R16, R16G increases agonist-mediated receptor down-regulation in both haplotypes (5). The importance of developing rapid ADRB2 screening protocols that differentiate codon 16/27 diplotypes is emphasized by the number of studies linking these genotypes to clinical and pharmacologic responses. SNPs representing the partial haplotype at codons 16 and 27 are variously associated with altered vasodilation (6) and high blood pressure (7), play roles in the development of type II diabetes (8), and have been linked to preterm delivery (9), agonist desensitization (10), albuterol responses (11), increased IgE in asthmatic families (12), obesity (13), hypertriglyceridemia, and development of fatty liver (14). Methods to routinely detect the common codon 16 and 27 polymorphisms have relied on preliminary amplification of ADRB2 sequences by PCR and subsequent identification by …

The pro-apoptotic prostate apoptosis response-4 gene product Par-4 sensitizes prostate cells to the induction of programmed cell death. In this study we examined Par-4 expression in human melanoma cell lines and melanoma metastases. The heterogeneous expression detected prompted us to investigate the biological relevance of Par-4 in a human melanoma xenotransplantation model. Overexpression of Par-4 by transfection decreased tumour development in xenotransplanted A375-C6 melanoma cells in SCID mice and correlated to an increase in tumour cell apoptosis. These data suggest that high expression of the pro-apoptotic protein Par-4 could qualify as a prognostic marker in human melanoma.