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Chemoradiotherapy (CRT) represents a standard treatment for many human cancers, frequently combined with radical surgical resection. However, a considerable percentage of primary cancers are at least partially resistant to CRT, which represents a substantial clinical problem, because it exposes cancer patients to the potential side effects of both irradiation and chemotherapy. It is therefore exceedingly important to determine the molecular characteristics underlying CRT-resistance and to identify novel molecular targets that can be manipulated to re-sensitize resistant tumors to CRT. In this review, we highlight much of the recent evidence suggesting that the signal transducer and activator of transcription 3 (STAT3) plays a prominent role in mediating CRT-resistance, and we outline why inhibition of STAT3 holds great promise for future multimodal treatment concepts in oncology. peerReviewed

Increased activity of signal transducer and activator of transcription 3 (STAT3) is common in human malignancies, including colorectal cancers (CRCs). We have recently reported that STAT3 gene expression correlates with resistance of CRC cell lines to 5-fluorouracil (5-FU)-based chemoradiotherapy (CT/RT). This is of considerable clinical importance, because a large proportion of rectal cancers are resistant to preoperative multimodal treatment. To test whether STAT3 contributes to CT/RT-resistance, we first confirmed that STAT3 protein expression correlated positively with increasing resistance. While STAT3 was not constitutively active, stimulation with interleukin-6 (IL-6) resulted in remarkably higher expression levels of phosphorylated STAT3 in CT/RT-resistant cell lines. A similar result was observed when we determined IL-6-induced expression levels of phosphorylated STAT3 following irradiation. Next, STAT3 was inhibited in SW480 and SW837 using siRNA, shRNA and the small-molecule inhibitor STATTIC. Successful silencing and inhibition of phosphorylation was confirmed using Western blot analysis and a luciferase reporter assay. RNAi-mediated silencing as well as STATTIC treatment resulted in significantly decreased clonogenic survival following exposure to 3 µM of 5-FU and irradiation in a dose-dependent manner, with dose-modifying factors of 1.3-2.5 at a surviving fraction of 0.37. Finally, STAT3 inhibition led to a profound CT/RT-sensitization in a subcutaneous xenograft model, with a significantly delayed tumor regrowth in STATTIC-treated mice compared with control animals. These results highlight a potential role of STAT3 in mediating treatment resistance and provide first proof of concept that STAT3 represents a promising novel molecular target for sensitizing resistant rectal cancers to CT/RT.

Background: In recent years remarkable ethnic/racial differences in the frequency of prostate cancer (CaP) driver gene alterations have emerged. Along the lines of ethnic differences in CaP genomes, oncogenic activation of ERG proto-oncogene and deletion of the PTEN tumor suppressor gene are most widely studied. These findings underscore distinct biology of prostate cancer in different ethnicities and races. We have reported the cumulative analyses of 435 patients (whole genome sequencing (WGS): 14, FISH evaluations: 101, SNP array: 320) comparing CaP genomes of African American (AA) and Caucasian American (CA) patients. An AA CaP genome-associated deletion was identified and mapped to the Limbic System-Associated Membrane Protein (LSAMP) gene locus. Further examination of the data indicated the AA CaP-genome associated deletion of the Chromodomain Helicase DNA Binding Protein 1(CHD1) gene. The goal of the current study is the comparative assessment of frequencies and prognostic associations of CaP genome alterations in the context of racial/ethnic differences. Methods: A prostate tumor tissue microarray (TMA) of benign and tumor foci (500+ cores) was generated by sampling 2-3 cores representing the range of cell morphology in matched cohort of 42 AA and 59 CA patients with up to 20 years of follow-up. Comparative evaluation of frequencies and prognostic associations of ERG oncoprotein by immunohistochemistry and the deletion of LSAMP, CHD1, and PTEN genes by FISH was performed. ERG frequencies were further assessed in index tumors of Chinese CaPs (N=100) and were compared to ERG frequencies in index tumors of patients from the United States equal-access military health-care system (N=336 AA and N=594 CA). Results: Higher frequencies of recurrent deletions of CHD1 (29% AA vs. 10% CA p=0.017) and LSAMP (26% AA vs. 7% CA, p=0.006) were identified in AA CaP compared to CA CaPs. These deletions were associated with significantly higher risk of rapid biochemical recurrence. In contrast, PTEN deletions (15% AA vs. 63% CA) and the frequency of ERG positive CaPs (26% AA vs. 64% CA) were more frequent among CA CaPs. Comparative evaluation of ERG frequencies in CaPs (N=1,292) underscores highest ERG frequency among CA patients (49.3%) followed by AA (23.2%) and Chinese (22%) men. Conclusions: In light of distinct biology of CaPs in ethnically/racially diverse CaP patient populations, there is a need for developing broadly applicable diagnostic, prognostic marker panels and therapeutic approaches. Higher frequency of CHD1 deletion in CaPs of AA patients may provide new therapeutic opportunities due to the sensitivity of CHD1 deletion harboring tumors to PARP inhibitors and platinum agents. Acknowledgments: This research was supported by the CPDR-USU program HU0001-10-2-0002, the National Cancer Institute R01CA162383 grant, the EDRN/NCI ACN12011-001-0 grant, the Snyder Medical Foundation, the Otto Mønsteds Foundation, the Mazzone Foundation, the Breast Cancer Research Foundation, the Novo Nordisk Foundation, and grants by MTA-TKI643/2012, KTIA_NAP_13-2014-0021. Citation Format: Albert Dobi, Gyorgy Petrovics, Hua Li, Denise Young, Shyh-Han Tan, Yongmei Chen, Qingyu Xiao, Yidi Sun, Hong Li, Yixue Li, Yuan Ji, Jun Hou, Wendy Wang, Jacob Kagan, Guo-Ping Zhao, Sudhir Srivastava, Reinhard Ebner, Inger L. Rosner, Jennifer Cullen, Matthew Freedman, Isabell Sesterhenn, Zoltan Szallasi, Shiv Srivastava. Distinct genomic alterations in prostate cancer of African American men [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A018.

Background: Distinct biology of prostate cancer (CaP) among men of different races and ethnicities have been recently highlighted. Along these lines higher frequencies of the most common CaP gene alterations, ERG proto-oncogene activation and deletion of the PTEN tumor suppressor, have been reported among Caucasian Americans (CA) when compared to other racial/ethnic groups. We have reported the cumulative analyses of CaPs from 435 patients (whole genome sequencing (WGS), FISH evaluations and SNP arrays) that highlighted the recurrent deletion and disease progression association of the Limbic System-Associated Membrane Protein (LSAMP) in CaP genomes of African American (AA) men. Further examination of these data indicated the AA CaP genome associated recurrent deletion of the Chromodomain Helicase DNA Binding Protein 1(CHD1) gene. Methods: Combined evaluation of frequencies and prognostic associations of ERG oncoprotein by immunohistochemistry and deletions of LSAMP, CHD1 and PTEN genes by FISH were performed using a multi-core TMA (42 AA and 59 CA patients) with longitudinal follow up data (median 16 years). CaP and matched blood genomic DNA samples (N=60) from AA patients were analyzed by WGS. ERG frequencies were further evaluated in index tumors of Chinese CaPs (N=100) and were compared to ERG frequencies in index tumors of AA (N=336) and CA (N=594) patients. Results: Frequent deletions of CHD1 (29% AA vs. 10% CA p=0.017) and LSAMP (26% AA vs. 7% CA, p=0.006) were found in AA CaPs by FISH assay. Both of these deletions were associated with rapid disease progression. Evaluation of CaPs by WGS further highlighted the recurrent deletion of CHD1 among AA men. Comparative evaluation of ERG (AA, N=336; CA, N=594, and Asian N=100) underscored highest ERG frequencies among CA patients (49.3%) followed by AA (23.2%) and Chinese (22%) men. Conclusions: In light of distinct biology of CaPs in ethnically/racially diverse CaP patient populations there is a need for developing broadly applicable diagnostic, prognostic marker panels and therapeutic approaches. Recurrent CHD1 deletion in CaPs of AA patients may provide new therapeutic opportunities in light of recent reports suggesting that CaP patients harboring CHD1 deletion may benefit from PARP inhibitor or platinum agents therapies. Funding: This study was supported by CPDR, USUHS, HU0001-10-2-0002 to I.L.R., the NCI/EDRN IAA ACN12011-001-0 to S.S. and by the NCI R01CA162383 to S.S. Citation Format: Albert Dobi, Gyorgy Petrovics, Shyh-Han Tan, Hua Li, Denise Young, Cara Schafer, Jesse Fox, Kevin Babcock, Heng-Cheng Hu, Gauthaman Sukumar, Yingjie Song, Lakshmi Ravindranath, Yongmei Chen, Joseph Cheng, Reinhard Ebner, Qingyu Xiao, Yidi Sun, Yixue Li, Yuan Ji, Jun Hou, Wendy Wang, Guo-Ping Zhao, Jacob Kagan, Sudhir Srivastava, Joel T. Moncur, Clifton L. Dalgard, Matthew Wilkerson, Inger L. Rosner, Jennifer Cullen, Matthew Freedman, Zoltan Szallasi, Isabell A. Sesterhenn, Shiv Srivastava. Racial/ethnic differences in prostate cancer genomic alterations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5352.

This abstract is being presented as a short talk in the scientific program. A full abstract is printed in the Proffered Abstracts section (PR01) of the Conference Proceedings. Note: This abstract was not presented at the conference. Citation Format: Albert Dobi, Gyorgy Petrovics, Hua Li, Denise Young, Yongmei Chen, Jacob Kagan, Sudhir Srivastava, Reinhard Ebner, Inger L. Rosner, Jennifer Cullen, Matthew L. Freedman, Isabell A. Sesterhenn, Zoltan Szallasi, Shiv Srivastava. Distinct genomic alterations in prostate cancer of African American men [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr B57.

Background: Emerging observations highlight distinct biology of prostate cancer (CaP) among men of different ethnicities and races. Studies including reports from our institute have demonstrated remarkable ethnic/racial differences in the frequency of ERG oncogenic activation, one of the most common and widely studied CaP driver genes. Similarly, deletion of the PTEN tumor suppressor gene, an established cancer driver gene alteration, was shown to be more prevalent among men of European ancestry. We have reported the cumulative analyses of 435 patients (whole-genome sequencing [WGS]: 14, FISH evaluations: 101, SNP array: 320) comparing CaP genomes of African American and Caucasian American patients. An AA CaP genome associated minimum deletion site on 3q13.31 was identified by WGS and mapped to the Limbic System-Associated Membrane Protein (LSAMP) gene locus using the TCGA SNP array data of 44 AA and 260 CA tumors. Further, we also noted the AA CaP genome association of the Chromodomain Helicase DNA Binding Protein 1(CHD1) gene deletion. Methods: The frequency and prognostic associations of LSAMP, CHD1, and PTEN deletions was evaluated by FISH analyses in prostate tumor tissue microarray (TMA) with up to 20 years of follow-up. The TMA represented normal and tumor foci (1000+ cores) sampled by 2-3 cores including the spectrum of cell morphology and tumor pathology in matched cohort of 42 AA and 59 CA patients. ERG was evaluated in the same TMA by immunohistochemistry. Evaluation of ERG was extended to the assessment of whole mounted prostate sections of 336 AA and 594 CA patients from the equal-access military health care system, in which disparities in socioeconomic status, health awareness, and physical activity are minimized. Results: AA CaP genome-associated recurrent deletions of LSAMP (26% AA vs. 7% CA, p=0.006) and CHD1 (29% AA vs. 10% CA p=0.017) genes were identified. AA CaP patients harboring these genomic deletions in their CaP showed significantly higher risk of rapid disease progression as measured by biochemical recurrence. Consistent with previous reports, we noted significantly lower frequency of PTEN deletions (15% AA vs. 63% CA) and ERG expression (26% AA vs. 64%) in prostate cancers among AA men. In-depth evaluation of ERG frequencies in the context of multifocal disease provided definitive evidence for the difference in the frequency of ERG between AA (23%) and CA (49%) patients from the equal-access military health care system. Conclusions: Our study underscores that the biology of CaP has to be taken into consideration when new diagnostic and prognostic markers and therapeutic approaches are being developed in order to realize the true potential of precision medicine for all cancer patients. Note: This abstract was not presented at the conference. Citation Format: Albert Dobi, Gyorgy Petrovics, Hua Li, Denise Young, Yongmei Chen, Jacob Kagan, Sudhir Srivastava, Reinhard Ebner, Inger L. Rosner, Jennifer Cullen, Matthew L. Freedman, Isabell A. Sesterhenn, Zoltan Szallasi, Shiv Srivastava. Distinct genomic alterations in prostate cancer of African American men [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr PR01.

Although used in academic research for several decades, 3D culture models have long been regarded expensive, cumbersome and unnecessary in drug development processes. Technical advances, coupled with recent observations showing that gene expression in 3D is much closer to clinical expression profiles than those seen in 2D, have renewed attention and generated hope in the feasibility of maturing organotypic 3D systems to therapy test platforms with greater power to predict clinical efficacies. Here we describe a standardized setup for reproducible, easy-handling culture, treatment and routine analysis of multicellular spheroids, the classical 3D culture system resembling many aspects of the pathophysiological situation in human tumor tissue. We discuss essential conceptual and practical considerations for an adequate establishment and use of spheroid-based drug screening platforms and also provide a list of human carcinoma cell lines, partly on the basis of the NCI-DTP 60-cell line screen, that produce treatable spheroids under identical culture conditions. In contrast to many other settings with which to achieve similar results, the protocol is particularly useful to be integrated into standardized large-scale drug test routines as it requires a minimum number of defined spheroids and a limited amount of drug. The estimated time to run the complete screening protocol described herein--including spheroid initiation, drug treatment and determination of the analytical end points (spheroid integrity, and cell survival through the acid phosphatase assay)--is about 170 h. Monitoring of spheroid growth kinetics to determine growth delay and regrowth, respectively, after drug treatment requires long-term culturing (> or =14 d).

Background: Radical paradigm shifts in traditional thinking is paramount to winning the war on cancer and understanding why this disease survives even the most brutal of toxic therapies. There is mounting evidence that biophysical signals are integral to the cycle of initiation, progression and death of cancer cells. Innovative technologies that manipulate this vulnerability in solid tumors could effectively be used to perturb only diseased cells and tissues. Not compromising normally functioning cells while controlling tumor progression, is the ultimate goal for evolving cancer therapeutics like Quantum Magnetic Resonance Therapy, headed promisingly in that direction. Methods: A patented, CE marked device, the CYTOTRON® delivers rotating, target-specific, modulated, safe Radio Frequencies in the presence of an integrated, instantaneous magnetic field. The presumed modulation of the transmembrane potential of tumor cells and downstream cellular signalling by RF for tissue degeneration in cancer underlies Rotational Field Quantum Magnetic Resonance platform technology. Whole body MRI for tissue proton density determinations was used to compute individualized dosimetry to target solitary or multiple regions of interest in the whole body, simultaneously. Exposure to QMRT was for 1 hour daily for 28 consecutive days. Quality of Life assessments, overall survival and tumor stability using RECIST v1.1 were followed up for 12 months. Results: Significant increase in life expectancy from the predicted to the actual mean (p=2.13 E-12), and improvements in Karnofsky Performance Scale scores (p=7.25 E-06) and Quality of Life scores (p=1.71 E-08 and p=1.91 E-06) were noted. Thirty six of 51 (71 %) terminally ill patients had stable disease one month after completion of QMRT or longer. Conclusions: Exposure to radiofrequency-mediated QMRT improved life expectancy and quality of life, along with arrest of tumor progression. This therapy can be safely positioned in a palliative care setting, transitioning to mainstream cancer care with more rigorous clinical validation.

Cell-based assays are more complex than cell-free test systems but still reflect a highly artificial cellular environment. Incorporation of organotypic 3-dimensional (3-D) culture systems into mainstream drug development processes is increasingly discussed but severely limited by complex methodological requirements. The objective of this study was to explore a panel of standard assays to provide an easy-handling, standardized protocol for rapid routine analysis of cell survival in multicellular tumor spheroid-based antitumor drug testing. Spheroids of 2 colon carcinoma cell lines were characterized for evaluation. One of the assay systems tested could reliably be used to determine cell viability in spheroids. The authors verified that the acid phosphatase assay (APH) is applicable for single spheroids in 96-well plates, does not require spheroid dissociation, and is linear and highly sensitive for HT29 and HCT-116 spheroids up to diameters of 650 microm and 900 microm, consisting of 40,000 and 80,000 cells, respectively. Treatment of HT29 and HCT-116 cells with 5-fluorouracil, Irinotecan, and C-1311 revealed critically reduced drug efficacies in 3-D versus monolayer culture, which is discussed in light of literature data. The experimental protocol presented herein is a small but substantial contribution to the establishment of sophisticated 3-D in vitro systems in the antitumor drug screening scenario.

Progress in cancer treatment has been slow, and the outlook for curing cancer is only marginally different from the situation a decade ago. Paradoxically, although the pharmaceutical industry has stepped up costly discovery research and drug development, approvals are on the decline and pipelines are dwindling. In an effort to reduce the number of drug failures and curtail burgeoning R&D costs, drug companies are exploring the use of biomarkers to evaluate toxicity and efficacy earlier in the development process. Biomarkers hold promise for optimization in dosing, adverse event prediction, efficacy evaluation, lead prioritization, and mechanism-of-action profiling of drug candidates. Furthermore, clinicians can use biomarkers to monitor patient response in clinical trials. In this perspective article, the authors explore the applications of cancer-related expression biomarkers in drug discovery and discuss how this will impact the industry and benefit the patient.

BACKGROUND The understanding of the molecular biology of the prostate and the process of prostate carcinogenesis is brought forward by the identification and characterization of new genes specifically expressed in prostate tissue. The encoded proteins may, in addition, provide novel diagnostic and therapeutic tools in prostate carcinoma (PCa). Here, we identify the novel gene Dresden-transmembrane protein of the prostate (D-TMPP) that is overexpressed in human prostate and prostate cancer. METHODS Proceeding from a prostate-specific expressed sequence tag identified with an Affymetrix chip-based expression database, the full-length cDNA of the novel gene was isolated from prostate tissue. The potential protein-coding function of the open reading frame (ORF) was tested by in vitro transcription-coupled translation and recombinant expression in transfected prostate cancer cells. The expression pattern of D-TMPP in malignant and nonmalignant tissues and tumor cell lines was analyzed by hybridization of a radioactively labeled cDNA probe with a multiple tissue expression array and by a quantitative real-time PCR assay. RESULTS The D-TMPP-mRNA encodes a putative seven-span transmembrane protein of 883 amino acids and is selectively overexpressed in prostate tissue. D-TMPP represents the first cloned and characterized transcript of a family of eukaryotic genes. D-TMPP transcripts were detected in all analyzed pairs (n = 25) of malignant and nonmalignant prostate tissues. In the androgen-dependent PCa cell line LNCaP, D-TMPP was upregulated by methyltrienolone. CONCLUSIONS We describe the novel prostate-restricted molecule D-TMPP widely expressed in prostate cancer tissues. © 2005 Wiley-Liss, Inc.

The use of molecular targets in novel strategies of tumor treatment largely depends on the identification of proteins with a tumor- or tissue-restricted expression. We identified the novel protein D-GPCR that is selectively overexpressed in human prostate cancer and prostate and belongs to the subfamily of odorant-like orphan G protein-coupled receptors. Quantification of D-GPCR transcripts in different human tissues by real-time PCR demonstrated 27-fold overexpression in prostate compared to skeletal muscle, the organ with second highest transcript numbers in males. Investigation of tumor/normal cDNA pairs obtained from 241 cancer patients including four prostate tumors confirmed the preferential expression in prostate. When comparing the mean transcript level of 15 prostate cancer tissues to their non-tumorous counterparts, D-GPCR was almost 6-fold upregulated. Coupled in vitro transcription and translation of D-GPCR cDNA produced a protein band of approximately 28 kDa. Recombinant, His-tagged protein was expressed in transfected HEK293 cells and gave rise to a 30 kDa band specifically detected by anti-His antibody. These data provide the basis for future studies evaluating the diagnostic potential of D-GPCR and its utility as a novel target in immunotherapy of prostate cancer.

Over the past few years, establishment and adaptation of cell-based assays for drug development and testing has become an important topic in high-throughput screening (HTS). Most new assays are designed to rapidly detect specific cellular effects reflecting action at various targets. However, although more complex than cell-free biochemical test systems, HTS assays using monolayer or suspension cultures still reflect a highly artificial cellular environment and may thus have limited predictive value for the clinical efficacy of a compound. Today's strategies for drug discovery and development, be they hypothesis free or mechanism based, require facile, HTS-amenable test systems that mimic the human tissue environment with increasing accuracy in order to optimize preclinical and preanimal selection of the most active molecules from a large pool of potential effectors, for example, against solid tumors. Indeed, it is recognized that 3-dimensional cell culture systems better reflect the in vivo behavior of most cell types. However, these 3-D test systems have not yet been incorporated into mainstream drug development operations. This article addresses the relevance and potential of 3-D in vitro systems for drug development, with a focus on screening for novel antitumor drugs. Examples of 3-D cell models used in cancer research are given, and the advantages and limitations of these systems of intermediate complexity are discussed in comparison with both 2-D culture and in vivo models. The most commonly used 3-D cell culture systems, multicellular spheroids, are emphasized due to their advantages and potential for rapid development as HTS systems. Thus, multicellular tumor spheroids are an ideal basis for the next step in creating HTS assays, which are predictive of in vivo antitumor efficacy.

By screening a transcriptome database for expressed sequence tags that are specifically expressed in mammary gland and breast carcinoma, we identified a new human cytochrome P450 (CYP), termed CYP4Z1. The cDNA was cloned from the breast carcinoma line SK-BR-3 and codes for a protein of 505 amino acids. Moreover, a transcribed pseudogene CYP4Z2P that codes for a truncated CYP protein (340 amino acids) with 96% identity to CYP4Z1 was found in SK-BR-3. CYP4Z1 and CYP4Z2P genes consisting of 12 exons are localized in head-to-head orientation on chromosome 1p33. Tissue-specific expression was investigated using real-time reverse transcription PCR with normalized cDNA from 18 different human tissues. CYP4Z1 mRNA was preferentially detected in breast carcinoma tissue and mammary gland, whereas only marginal expression was found in all other tested tissues. Investigation of cDNA pairs from tumor/normal tissues obtained from 241 patients, including 50 breast carcinomas, confirmed the breast-restricted expression and showed a clear overexpression in 52% of breast cancer samples. The expression profile of CYP4Z2P was similar to that of CYP4Z1 with preference in breast carcinoma and mammary gland but a lower expression level in general. Immunoblot analyses with a specific antiserum for CYP4Z1 clearly demonstrated protein expression in mammary gland and breast carcinoma tissue specimens as well as in CYP4Z1-transduced cell lines. Confocal laser-scanning microscopy of MCF-7 cells transfected with a fluorescent fusion protein CYP4Z1-enhanced green fluorescent protein and a subcellular fractionation showed localization to the endoplasmic reticulum as an integral membrane protein concordant for microsomal CYP enzymes.

Identification of genes selectively expressed in tumors or individual tissues is a crucial prerequisite for molecular diagnosis and treatment of cancer by addressing molecular targets. By screening an expression database, we identified the novel gene D-PCa-2 (Dresden prostate carcinoma 2), which is highly overexpressed in normal prostate tissue and prostate carcinoma (PCa). The corresponding transcript contained an open reading frame of 453 nucleotides encoding a putative protein of 150 amino acids. A large part of exon 8 of the D-PCa-2 gene shows strong similarity to the high-mobility-group nucleosomal binding protein 2 (HMGN2) cDNA. The highly specific transcription of the D-PCa-2 gene in normal and malignant prostate tissues and in a few additional tumors was demonstrated by using multiple tissue dot blot, cancer profiling dot blot and real-time PCR analyses. Examination of 18 pairs of tumorous and nontumorous prostate tissues from PCa patients by quantitative RT-PCR revealed D-PCa-2 transcripts in all specimens. The potential usefulness of D-PCa-2 as a sensitive marker for metastatic prostate carcinoma cells in lymph nodes was demonstrated by the detection of one LNCaP cell in 1 x 10(5) normal lymph node cells using real-time RT-PCR. Examination of 22 lymph nodes from PCa patients either containing metastatic prostate cancer cells or diagnosed as cancer-free was in full concordance with histopathologic diagnoses. These results validate D-PCa-2 as a transcript with high tissue specificity and with a potential application in the diagnosis of PCa.

Evaluation of cancer genomes in global context is of great interest in light of changing ethnic distribution of the world population. We focused our study on men of African ancestry because of their disproportionately higher rate of prostate cancer (CaP) incidence and mortality. We present a systematic whole genome analyses, revealing alterations that differentiate African American (AA) and Caucasian American (CA) CaP genomes. We discovered a recurrent deletion on chromosome 3q13.31 centering on the LSAMP locus that was prevalent in tumors from AA men (cumulative analyses of 435 patients: whole genome sequence, 14; FISH evaluations, 101; and SNP array, 320 patients). Notably, carriers of this deletion experienced more rapid disease progression. In contrast, PTEN and ERG common driver alterations in CaP were significantly lower in AA prostate tumors compared to prostate tumors from CA. Moreover, the frequency of inter-chromosomal rearrangements was significantly higher in AA than CA tumors. These findings reveal differentially distributed somatic mutations in CaP across ancestral groups, which have implications for precision medicine strategies.

As part of a large scale effort to discover novel secreted proteins, a cDNA encoding a novel cytokine was identified. Alignments of the sequence of the new protein, designated IL-17B, suggest it to be a homolog of the recently described T cell-derived cytokine, IL-17. By Northern analysis, EST distribution and real-time quantitative polymerase chain reaction analysis, mRNA was detected in many cell types. A novel type I transmembrane protein, identified in an EST data base by homology to IL-17R, was found to bind specifically IL-17B, as determined by surface plasmon resonance analysis, flow cytometry, and co-immunoprecipitation experiments. Readily detectable transcription of IL-17BR was restricted to human kidney, pancreas, liver, brain, and intestines and only a few of the many cell lines tested. By using a rodent ortholog of IL-17BR as a probe, IL-17BR message was found to be drastically up-regulated during intestinal inflammation elicited by indomethacin treatment in rats. In addition, intraperitoneal injection of IL-17B purified from Chinese hamster ovary cells caused marked neutrophil migration in normal mice, in a specific and dose-dependent manner. Together these results suggest that IL-17B may be a novel proinflammatory cytokine acting on a restricted set of target cell types. They also demonstrate the strength of genomic approaches in the unraveling of novel biological pathways.

MAX.3 is a monoclonal antibody that preferentially reacts with mature macrophages (MAC), monocyte-derived dendritic cells, megakaryocytes and platelets. In this study, we describe the characterization, purification and identification of the MAX.3 antigen. Immunoprecipitation and SDS/PAGE revealed different molecular masses of MAX.3 antigen in MAC (60-90 kDa) and platelets (58-64 kDa), whereas a similar size (45 kDa) was observed in both cell types after digestion with N-glycosidase F. Lectin affinity and sequential treatment with different glycosidases suggests complex type glycosylation of MAX.3 antigen in MAC and hybrid type glycosylation in platelets. Amino acid sequencing led to the identification of a corresponding cDNA clone and showed its identity to the sequence of the CD84 antigen, a member of the CD2 family of cell surface molecules. MAX.3/CD84 was further studied by immunohistochemistry and a variable expression was found on tissue MAC, confirming this antigen to be mainly a marker for MAC in situ.

One of the universal characteristics of the long bones and spines of middle-age and older mammals is a loss in bone mass (osteopenia). In humans, if this bone loss is severe enough, it results in osteoporosis, a skeletal disorder characterized by a markedly increased incidence of fractures with sequelae that may include pain, loss of mobility, and in the event of hip fracture, even death within a relatively few months of injury. An important contributing factor to the development of osteopororsis appears to be a diminution in the number and activity of osteoblasts responsible for synthesizing new bone matrix. The findings in the present and other similar studies suggest that this reduction in osteoblast number and activity is due to an age-related diminution in the size and osteogenic potential of the bone marrow osteoblast progenitor cell (OPC or CFU-f) compartment. We previously postulated that these regressive changes in the OPC/CFU-f compartment occurred in old animals because of a reduction in the amount and/or activity of TGF-β1, an autocrine growth factor important in the promotion of OPC/CFU-f proliferation and differentiation. In support of this hypothesis, we now report that (1) the osteogenic capacity of the bone marrow of 24-month-old BALB/c mice, as assessed in vivo, is markedly reduced relative to that of 3–4-month-old animals, (2) that the matrix of the long bones of old mice contains significantly less TGF-β than that of young mice, (3) that OPC's/CFU-f's isolated from old mice produce less TGF-β in vitro than those recovered from young mice, and (4) that OPC's/CFU-f's from old mice express significantly more TGF-β receptor (Types I, II, and III) than those of young animals and that such cells are more responsive in vitro to exogenous recombinant TGF-β1. We also find that colony number and proliferative activity of OPC's/CFU-f's of young mice and old mice, respectively, are significantly reduced when incubated in the presence of neutralizing TGF-β1 antibody. Collectively, these data are consistent with the hypothesis that in old male mice the reduction in the synthesis and, perhaps, availability from the bone matrix of TGF-β1 contributes to a diminution in the size and development potential of the bone marrow osteoprogenitor pool. J. Cell. Biochem. 70:478–488. © 1998 Wiley-Liss, Inc.

The Klebsiella pneumoniae genes scrA and scrB are indispensable for sucrose (Scr) utilisation. Gene scrA codes for an Enzyme IIScr (IIScr) transport protein of the phosphoenolpyruvate-dependent carbohydrate: phosphotransferase system (PTS), while scrB encodes a sucrose 6-phosphate specific invertase. A 3.7 kbscr AB DNA fragment has been cloned from K. pneumoniae and expressed in Escherichia coli. Its nucleotide sequence was determined and the coding regions for scrA (1371 bp) and scrB (1401 bp) were identified by genetic complementation, enzyme activity test and radiolabelling of the gene products. In addition, the nucleotide sequence of the scrB gene from conjugative plasmid pUR400 isolated from Salmonella typhimurium was also determined and errors in the previously published sequence of the scrA gene of pUR400 were corrected. Extensive similarity was found between the sequences of ScrA and other Enzymes II, as well as between the two invertases and other sucrose hydrolysing enzymes. Based on the analysis of seven IIScr proteins, a hypothetical model of the secondary structure of IIScr is proposed.

INTRODUCTION: Disproportionately higher rates of prostate cancer (CaP) incidence and mortality have been reported among African American (AA) men. Although oncogenic TMPRSS2-ERG gene fusion and deletion of the PTEN tumor suppressor gene are established cancer driver gene alterations in CaP, they are known to be more prevalent among men of European ancestry. By utilizing carefully annotated specimens, this study focused on the discovery of recurrent genomic alterations in CaP of AA men in comparison to Caucasian Americans (CA). METHODS: Genomic DNA from clinically localized primary prostate tumors (Gleason 6 or 7 with primary pattern 3) and matched peripheral blood lymphocytes of seven AA and seven CA patients, were analyzed by paired-end sequencing on Illumina Genome Analyzer IIx to a depth of 30x. Following alignment to reference genome, somatic alterations on tumor DNA that include single nucleotide variants (SNVs), insertion and deletions (Indels), structural variations, copy number variations, and inter- and intra-chromosomal translocations of tumor DNA sequence were identified. To confirm prevalent genomic deletions we performed FISH analysis on a tissue microarray constructed from 42 AA and 59 CA tumor and normal samples of an independent cohort. Frequently deleted loci were further validated by analysis of TCGA CaP SNP array data from 41 AA and 279 CA prostate tumors. RESULTS: A comparative evaluation of whole genome sequences of AA and CA CaP revealed a prevalent deletion of the LSAMP locus of chromosome 3q13.31 in AA CaP. These observations were confirmed by SNP array and FISH assays in independent cohorts of specimens. AA CaP patients with LSAMP deletion showed rapid disease progression. In contrast to higher frequency of LSAMP deletion, significantly lower frequencies of PTEN and ERG alterations were noted in CaP of AA men. Furthermore, CaP genomes of AA men displayed a higher rate of inter-chromosomal rearrangements than those from CA men. CONCLUSIONS: We highlight distinct features of AA and CA CaP genomes including common CaP driver genes (TMPRSS2- ERG, PTEN) and define a novel recurrent deletion of the LSAMP locus. This study underscores the need for careful evaluations of cancer genomes in underrepresented populations in the global context with implications for precision medicine strategies. Citation Format: Albert Dobi, Gyorgy Petrovics, Hua Li, Shyh-Han Tan, Tanja Stümpel, Denise Young, Shilpa Katta, Qiyuan Li, Kai Ying, Bernward Klocke, Lakshmi Ravindranath, Indu Kohaar, Yongmei Chen, Dezső Ribli, Korbinian Grote, Hau Zou, Joseph Cheng, Clifton L. Dalgard, Shimin Zhang, István Csabai, Jacob Kagan, David Takeda, Massimo Loda, Sudhir Srivastava, Matthias Scherf, Martin Seifert, Timo Gaiser, David G. McLeod, Zoltan Szallasi, Reinhard Ebner, Thomas Werner, Isabell A. Sesterhenn, Matthew Freedman, Shiv Srivastava. LSAMP gene deletion is associated with rapid disease progression in prostate cancer of African American men. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 140.

The secreted polypeptide transforming growth factor-beta (TGF-beta) exerts its multiple activities through type I and II cell surface receptors. In epithelial cells, activation of the TGF-beta signal transduction pathways leads to inhibition of cell proliferation and an increase in extracellular matrix production. TGF-beta is widely expressed during development and its biological activity has been implicated in epithelial-mesenchymal interactions, e.g., in branching morphogenesis of the lung, kidney, and mammary gland, and in inductive events between mammary epithelium and stroma. In the present study, we investigated the effects of TGF-beta on mouse mammary epithelial cells in vitro. TGF-beta reversibly induced an alteration in the differentiation of normal mammary epithelial NMuMG cells from epithelial to fibroblastic phenotype. The change in cell morphology correlated with (a) decreased expression of the epithelial markers E-cadherin, ZO-1, and desmoplakin I and II; (b) increased expression of mesenchymal markers, such as fibronectin; and (c) a fibroblast-like reorganization of actin fibers. This phenotypic differentiation displays the hallmarks of an epithelial to mesenchymal transdifferentiation event. Since NMuMG cells make high levels of the type I TGF-beta receptor Tsk7L, yet lack expression of the ALK-5/R4 type I receptor which has been reported to mediate TGF-beta responsiveness, we evaluated the role of the Tsk7L receptor in TGF-beta-mediated transdifferentiation. We generated NMuMG cells that stably overexpress a truncated Tsk7L type I receptor that lacks most of the cytoplasmic kinase domain, thus function as a dominant negative mutant. These transfected cells no longer underwent epithelial to mesenchymal morphological change upon exposure to TGF-beta, yet still displayed some TGF-beta-mediated responses. We conclude that TGF-beta has the ability to modulate E-cadherin expression and induce a reversible epithelial to mesenchymal transdifferentiation in epithelial cells. Unlike other transdifferentiating growth factors, such as bFGF and HGF, these changes are accompanied by growth inhibition. Our results also implicate the Tsk7L type I receptor as mediating the TGF-beta-induced epithelial to mesenchymal transition.

A considerable percentage of rectal cancers are resistant to standard preoperative chemoradiotherapy. Because patients with a priori-resistant tumors do not benefit from multimodal treatment, understanding and overcoming this resistance remains of utmost clinical importance. We recently reported overexpression of the Wnt transcription factor TCF4, also known as TCF7L2, in rectal cancers that were resistant to 5-fluorouracil-based chemoradiotherapy. Because Wnt signaling has not been associated with treatment response, we aimed to investigate whether TCF4 mediates chemoradioresistance. RNA interference-mediated silencing of TCF4 was employed in three colorectal cancer (CRC) cell lines, and sensitivity to (chemo-) radiotherapy was assessed using a standard colony formation assay. Silencing of TCF4 caused a significant sensitization of CRC cells to clinically relevant doses of X-rays. This effect was restricted to tumor cells with high T cell factor (TCF) reporter activity, presumably in a β-catenin-independent manner. Radiosensitization was the consequence of (i) a transcriptional deregulation of Wnt/TCF4 target genes, (ii) a silencing-induced G(2)/M phase arrest, (iii) an impaired ability to adequately halt cell cycle progression after radiation and (iv) a compromised DNA double strand break repair as assessed by γH2AX staining. Taken together, our results indicate a novel mechanism through which the Wnt transcription factor TCF4 mediates chemoradioresistance. Moreover, they suggest that TCF4 is a promising molecular target to sensitize resistant tumor cells to (chemo-) radiotherapy.

Studies on genetically engineered mouse models (GEMMs) have provided invaluable insights to our understanding of human tumors for nearly three decades. The ability to manipulate the murine genome with ever increasing sophistication has generated great expectations for their successful use in developing novel therapeutics. Indeed, GEMMs have shown remarkable power to faithfully recapitulate some key aspects of human tumorigenesis and therapy response. Yet, despite much enthusiasm generated during the early years of the new millennium, their use in drug discovery and development has remained limited. Economic, practical, licensing, historical, and regulatory considerations remain as hurdles to the robust utility of GEMMs in drug discovery and development as does the modest predictive abilities of any single model. Because cancer is a cellular and genetic disorder, advancing treatment options and cure rates will very likely continue to depend on the intelligent use of a combination of simple and complex experimental model systems, including biochemical, cell- and tissue-based and animal models. To date, the most pronounced impact that GEMMs have had on the biomedical industry has been in the areas of target and pathway validation, disease history elucidation, and the discovery and refinement of pharmacodynamic and toxicity biomarkers. There are also areas where GEMMs have tremendous potential but are currently underused, such as modeling metastatic disease spread, stem cell targeting, predictive marker testing, adaptive resistance modeling in vivo or ex vivo or the pharmacogenetic representation of heterogeneous patient populations.

Transforming growth factor-beta (TGF-beta) affects cellular proliferation, differentiation, and interaction with the extracellular matrix primarily through interaction with the type I and type II TGF-beta receptors. The type II receptors for TGF-beta and activin contain putative serine-threonine kinase domains. A murine serine-threonine kinase receptor, Tsk 7L, was cloned that shared a conserved extracellular domain with the type II TGF-beta receptor. Overexpression of Tsk 7L alone did not increase cell surface binding of TGF-beta, but coexpression with the type II TGF-beta receptor caused TGF-beta to bind to Tsk 7L, which had the size of the type I TGF-beta receptor. Overexpression of Tsk 7L inhibited binding of TGF-beta to the type II receptor in a dominant negative fashion. Combinatorial interactions and stoichiometric ratios between the type I and II receptors may therefore determine the extent of TGF-beta binding and the resulting biological activities.

Genes that are highly overexpressed in tumor cells can be required for tumor cell survival and have the potential to be selective therapeutic targets. In an attempt to identify such targets, we combined a functional genomics and a systems biology approach to assess the consequences of RNAi-mediated silencing of overexpressed genes that were selected from 140 gene expression profiles from colorectal cancers (CRCs) and matched normal mucosa. In order to identify credible models for in-depth functional analysis, we first confirmed the overexpression of these genes in 25 different CRC cell lines. We then identified five candidate genes that profoundly reduced the viability of CRC cell lines when silenced with either siRNAs or short-hairpin RNAs (shRNAs), i.e., HMGA1, TACSTD2, RRM2, RPS2 and NOL5A. These genes were further studied by systematic analysis of comprehensive gene expression profiles generated following siRNA-mediated silencing. Exploration of these RNAi-specific gene expression signatures allowed the identification of the functional space in which the five genes operate and showed enrichment for cancer-specific signaling pathways, some known to be involved in CRC. By comparing the expression of the RNAi signature genes with their respective expression levels in an independent set of primary rectal carcinomas, we could recapitulate these defined RNAi signatures, therefore, establishing the biological relevance of our observations. This strategy identified the signaling pathways that are affected by the prominent oncogenes HMGA1 and TACSTD2, established a yet unknown link between RRM2 and PLK1 and identified RPS2 and NOL5A as promising potential therapeutic targets in CRC.

Transforming growth factor-beta (TGF-beta) is a potent mediator of cell proliferation and extracellular matrix formation, depending on the cell type and the physiological conditions. TGF-beta is usually secreted in a "latent" complex that needs activation before it can exert its effects. Several observations correlate increased expression of TGF-beta 1 with tumorigenesis. To evaluate the physiological relevance of increased TGF-beta 1 synthesis in tumor cells we established cell clones overexpressing TGF-beta 1 and observed the resulting physiological changes in TGF-beta overproducing cells in vitro and in vivo. As a model system we used the human E1A-transformed 293 tumor cells, which are insensitive to the direct growth modulatory effects of TGF-beta. The selection of this cell line allows an assessment of physiological alterations independent of TGF-beta induced proliferative changes. The use of two TGF-beta 1 expression vectors containing either the natural or a modified TGF-beta 1 precursor cDNA permitted the establishment of separate 293 cell lines overexpressing latent or active TGF-beta. Comparison of the resulting changes in glycolytic rate, adhesiveness and integrin and plasminogen activator expression established that, in vitro, both types of clones behaved similarly, indicating that expression of latent TGF-beta induces autocrine changes in the tumor cells and thus suggesting that some level of cell-associated activation occurs. TGF-beta overexpression resulted in an increased metabolic rate due to enhanced glycolysis, a property long associated with tumor cells. This increased glycolysis was not associated with altered proliferation. Cells overexpressing TGF-beta also displayed enhanced fibronectin mRNA and plasminogen activator synthesis and increased adhesiveness in vitro. They showed enhanced survival when plated sparsely on plastic in the absence of serum, and attached more readily to laminin. In addition, synthesis of several beta 1 integrins, in particular the alpha 1/beta 1, alpha 2/beta 1, and alpha 3/beta 1, all of which recognize laminin, were enhanced. Finally, cells overexpressing active TGF-beta, but not latent TGF-beta, also showed increased tumorigenicity in nude mice. Thus, an increase in endogenous TGF-beta synthesis confers several proliferation-independent phenotypic changes which may be of significance for the survival of the tumor cell inoculum or its subsequent growth, and for tumor formation and development. In the case of cells expressing active TGF-beta, the release of active TGF-beta into the vicinity of the tumor cells may also result in a more hospitable environment for tumor growth.

To give a state-of-the-art overview on the promise of three-dimensional (3-D) culture systems for anticancer drug development, with particular emphasis on multicellular tumor spheroids (MCTS).Cell-based assays have become an integral component in many stages of routine anti-tumor drug testing. However, they are almost always based on homogenous monolayer or suspension cultures and thus represent a rather artificial cellular environment. 3-D cultures--such as the well established spheroid culture system--better reflect the in vivo behavior of cells in tumor tissues and are increasingly recognized as valuable advanced tools for evaluating the efficacy of therapeutic intervention. The present article summarizes past and current applications and particularly discusses technological challenges, required improvements and recent progress with the use of the spheroid model in experimental therapeutics, as a basis for sophisticated drug/therapy screening. A brief overview is given focusing on the nomenclature of spherical 3-D cultures, their potential to mimic many aspects of the pathophysiological situation in tumors, and currently available protocols for culturing and analysis. A list of spheroid-forming epithelial cancer cell lines of different origin is provided and the recent trend to use spheroids for testing combination treatment strategies is highlighted. Finally, various spheroid co-culture approaches are presented that have been established to study heterologous cell interactions in solid tumors and thereby are able to reflect the cellular tumor environment with increasing accuracy. The intriguing observation that in order to retain certain tumor initiating cell properties, some primary tumor cell populations must be maintained exclusively in 3-D culture is mentioned, adding a new but fascinating challenge for future therapeutic campaigns.

With recent advances in robotics and high-content screening and analysis methods, transcriptional profiling can now be utilized as a comprehensive forward chemical genomics platform for drug discovery, lead selection and lead optimization. It can be used to define the state of a cell on the basis of gene networks, and to search for drugs that can shift cellular states in a manner predicted at the genome level to be therapeutically beneficial. The treatment of cells with compounds produces transcriptional 'fingerprints' that reveal mechanism-of-action, and enable discrimination between individual compounds based on drug behaviors important to all phases of drug discovery and development.

Malignant glioma comprises the majority of primary human brain tumors with 16,800 new cases reported each year in the USA. Its prognosis remains dismal despite numerous attempts to improve conventional therapeutic modalities. Therefore, much effort is devoted to the exploration of alternative forms of treatment such as immunotherapy. The identification of potential target structures highly overexpressed in brain tumors is a crucial prerequisite for the activation of the immune defense against malignant glioma cells. By screening an expression database for genes highly expressed in glioblastoma multiforme (GBM), we identified the Pit-Oct-Unc (POU) cooperating transcription factor SOX11 that is known to be crucially involved in brain development. Analysis of the expression pattern of SOX11 in different normal adult and fetal tissues by multiple tissue dot blot and by a highly sensitive quantitative PCR assay confirmed the selective overexpression of SOX11 in fetal brain tissue. Examination of tissue specimens obtained from malignant gliomas and from normal brain by quantitative real-time PCR (Q-RT-PCR) revealed upregulation of SOX11 in almost all tumor samples (15/16) as compared to the pooled normal brain. Seventy-five percent of the tumor samples (12/16) showed a 5- to more than 600-fold overexpression. We conclude that, after downregulation of SOX11 in the adult brain, its expression is reactivated during tumorigenesis and that SOX11 therefore represents a promising novel molecular target for adjuvant therapy of malignant gliomas.

TR6 (decoy receptor 3 (DcR3)) is a new member of the tumor necrosis factor receptor (TNFR) family. TR6 mRNA is expressed in lung tissues and colon adenocarcinoma, SW480. In addition, the expression of TR6 mRNA was shown in the endothelial cell line and induced by phorbol 12-myristate 13-acetate/ionomycin in Jurkat T leukemia cells. The open reading frame of TR6 encodes 300 amino acids with a 29-residue signal sequence but no transmembrane region. Using histidine-tagged recombinant TR6, we screened soluble forms of TNF-ligand proteins with immunoprecipitation. Here, we demonstrate that TR6 specifically binds two cellular ligands, LIGHT (herpes virus entry mediator (HVEM)-L) and Fas ligand (FasL/CD95L). These bindings were confirmed with HEK 293 EBNA cells transfected with LIGHT cDNA by flow cytometry. TR6 inhibited LIGHT-induced cytotoxicity in HT29 cells. It has been shown that LIGHT triggers apoptosis of various tumor cells including HT29 cells that express both lymphotoxin beta receptor (LTbetaR) and HVEM/TR2 receptors. Our data suggest that TR6 inhibits the interactions of LIGHT with HVEM/TR2 and LTbetaR, thereby suppressing LIGHT- mediated HT29 cell death. Thus, TR6 may play a regulatory role for suppressing in FasL- and LIGHT-mediated cell death.

TRAIL (also known as Apo-2L) is a member of the tumor necrosis factor (TNF) ligand family that rapidly induces apoptosis in a variety of transformed cell lines. The human receptor for TRAIL was found to be an undescribed member of the TNF-receptor family (designated death receptor-4, DR4) that contains a cytoplasmic “death domain” capable of engaging the cell suicide apparatus but not the nuclear factor kappa B pathway in the system studied. Unlike Fas, TNFR-1, and DR3, DR4 could not use FADD to transmit the death signal, suggesting the use of distinct proximal signaling machinery. Thus, the DR4-TRAIL axis defines another receptor-ligand pair involved in regulating cell suicide and tissue homeostasis.

Transforming growth factor-β (TGF-β? is thought to play a role in mesenchymal cell development and, specifically, in muscle differentiation, yet its precise role in the latter process remains unclear. TGF-β has been shown to both inhibit and induce myoblast maturation in vitro, depending on the culture conditions. Whether the type I or type II TGF-β receptor mediates the various TGF-β effects on myogenesis is not known. In the present study, C2C12 myoblasts were transfected with an expression vector for a truncated type II TGF-β receptor, which has been shown to act as a dominant negative inhibitor of type II receptor signaling. In contrast to the parental cells, the transfected clones did not efficiently form myotubes or induce expression of MyoD, myogenin and several other differentiation markers following incubation in low serum media. However, some muscle differentiation markers continued to be expressed in the transfected cells suggesting that at least two pathways are involved in muscle cell differentiation. These cells could still growth arrest in low serum media, showing that decreased proliferation can be dissociated from differentiation. Unlike several oncogenes known to block myogenic differentiation, expression of the truncated TGF-β receptor did not result in myoblast transformation. Injection of the parental or the transfected C2C12 cells into the limb muscle of nude mice revealed quantitative and qualitative differences in their behavior, and suggested that myoblasts expressing the truncated TGF-β receptor cannot fuse in vivo. Finally, retrovirusmediated expression of MyoD in the transfected cells restored their ability to form myotubes in vitro, indicating that inhibition of myoblast differentiation by the truncated TGF-β receptor may depend on decreased MyoD expression. We propose that TGF-β signaling through the type II receptor is required for several distinct aspects of myogenic differentiation and that TGF-β acts as a competence factor in this multistep process.

We have isolated cDNAs of the murine type II TGF-β receptor and have found a conserved cytoplasmic domain, but a less extensive homology in the extracellular receptor domain between the human and murine homologues. In situ hybridization analysis of the mouse fetus during mid gestation localized the expression of this receptor to various developing tissues, primarily in the mesenchyme and epidermis. This expression pattern correlates well with the expression of TGF-β in general and especially TGF-β1, suggesting that TGF-β1 exerts its developmental role through this receptor in an autocrine or paracrine fashion. Type II receptor expression was not detected in the central nervous system and developing cartilage. These tissues lack TGF-β1 expression but express TGF-β2 and/or TGF-β3, suggesting that they may exert their activities through separate receptor isoforms. In addition, the efficient binding of TGF-β1, but not TGF-β2, to the cloned type II receptor strengthens the likelihood that additional type II receptor isoforms exist which display preferential binding to TGF-β2 and have their own defined role in development.

Rotational Field Quantum Magnetic Resonance (RFQMR) is a device-mediated novel therapeutic modality for cancer, currently in the clinical stage of development. It can also be used to deliver an electromagnetic force with strong, embedded, variable radio signals to induce Continuous Flow Focused Resonance Nano-permeabilization or CO-FORN concomitantly with drugs of choice for cancer treatment. Transient permeabilization of cells by Focused Resonance pulses induces a significant increase of anti-tumor drug concentration within the tumor and enables a practical solution to deliver valuable systemic chemotherapy and mitigate associated adverse effects. CO-FORN was administered to a refractory medullobalstoma patient who had previously received metronomic chemotherapy with Cyclophosphamide and VP16, significantly helping to reduce the associated cytotoxicity and myelosuppression commonly accompanying such treatment. The protocol allows for extremely accurate RFQMR dosing for therapeutic purposes. RFQMR can be applied as an extraneous source to permeate intractable tumors by creating molecular dimension-specific pore sizes. Targeted drug delivery is enabled thereby minimizing associated systemic drug toxicities. It has been shown that electroporation of cultured cells potentiates cytotoxicity of various chemotherapy agents and other targeted molecules by several hundred fold. This potentiation can be highly controlled using RFQMR by adjusting delivery parameters like molecular mass of the drug, peak plasma concentration, total tissue volume, cell membrane characteristics etc. Specific tumors can be resonated with high instantaneous magnetic fields and radio frequency (RF), followed by nano second signals which penetrate only resonating cells. The CO-FORN technique can potentiate antitumor effectiveness of drugs from 10 to 70 times and can be highly localized and used without implanting any electrodes, probes or particles into the body. Exposure to non-ionizing, non-thermal RFQMR does not cause uncontrollable destruction and entropy within the cell but more likely re-organizes related bio-structures. In principle, depending on the specific variations within the configured RFQMR, a predictable cell response can be expected. The technology allows for extremely accurate RFQMR dosing for therapeutic purposes. Of the several disease indications and applications that the device has been evaluated in extensive R&D efforts at the Center for Advanced Research & Development (CARD) in Bangalore India, the use of RFQMR to permeabilize tumors in conjunction with systemic chemotherapy, is an innovative application. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C102.

Background: The clinical response of locally advanced rectal cancers to preoperative chemoradiotherapy is very heterogeneous. We recently profiled a series of responsive and resistant rectal carcinomas using gene expression microarrays and identified TCF7L2, the main downstream effector of the Wnt/β-catenin pathway, as over-expressed in the resistant tumors. The aim of this study was to explore the relevance of TCF7L2 for resistance to radiation and to study the underlining mechanisms. Methods: We transfected three microsatellite-stable colorectal cancer cell lines (SW837, SW480 and HT-29) with two different shRNA-vectors targeting TCF7L2 and a non-silencing. Next, we established single cell clone (SCC) populations, and after confirming the reduction of TCF7L2 protein levels by Western blotting, we irradiated the SCCs at 0, 1, 2, 4, 6 and 8 Gy and calculated survival fractions. To gain functional insight, we chose SW837 and HT-29 for further experiments. Using γH2AX staining we evaluated DNA double strand repair after irradiation at 2 Gy and analyzed cell cycle changes before and after radiation. Furthermore, we studied Wnt/β-catenin pathway activity using the TOPFLASH/FOPFLASH reporter assay. Results: RNAi-mediated silencing of TCF7L2 led to a pronounced reduction in TCF7L2 protein levels. In radiation experiments we observed a highly significant radiosensitization in SW837 and SW480 SCCs, whereas no effect was observed in HT-29 SCCs. Well-fitting, we observed significantly more γH2AX foci 24h after radiation in SW837 SCCs compared to HT-29 SCCs, pointing to impaired DNA damage repair in the SCCs from SW837. Furthermore, in SW837 SCCs but not in HT-29 SCCs we noticed a change in the cell cycle distribution towards radiosensitive cell cycle phases before radiation and compromised cell cycle control after radiation. Finally, using the TOPFLASH/FOPFLASH reporter assay we found SW837 wild-type cells to show high Wnt/β-catenin pathway activity, while HT-29 wild-type cells only showed very low activity. Conclusion: TCF7L2 was found to be over-expressed in resistant rectal carcinomas, and its RNAi-mediated silencing caused a significant radiosensitization, mediated by DNA damage repair deficiencies and impaired cell cycle control. Interestingly, radiosensitization effetcts were only observed in cell lines showing Wnt/β-catenin pathway activity. Thus, we have uncovered a novel role of Wnt/β-catenin signaling for mediating resistance to multimodal cancer therapy. Moreover, these data suggest that TCF7L2 is a potential molecular target for sensitizing Wnt/β-catenin-dependent tumor cells to radiation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2490. doi:10.1158/1538-7445.AM2011-2490

Transforming growth factor-beta (TGF-beta) and activin signal primarily through interaction with type I and type II receptors, which are transmembrane serine-threonine kinases. Tsk 7L is a type I receptor for TGF-beta and requires coexpression of the type II TGF-beta receptor for ligand binding. Tsk 7L also specifically bound activin, when coexpressed with the type IIA activin receptor. Tsk 7L could associate with either type II receptor and the ligand binding specificity of Tsk 7L was conferred by the type II receptor. Tsk 7L can therefore act as type I receptor for both activin and TGF-beta, and possibly other ligands.

Transforming growth factor-beta (TGF-beta) is a multifunctional protein that regulates cell proliferation and differentiation and extracellular matrix production. Although two receptor types, the type I and type II receptors, have been implicated in TGF-beta-induced signaling, it is unclear how the many activities of TGF-beta are mediated through these receptors. With the use of cells overexpressing truncated type II receptors as dominant negative mutants to selectively block type II receptor signaling, the existence of two receptor pathways was shown. The type II receptors, possibly in conjunction with type I receptors, mediate the induction of growth inhibition and hypophosphorylation of the retinoblastoma gene product pRB. The type I receptors are responsible for effects on extracellular matrix, such as the induction of fibronectin and plasminogen activator inhibitor I, and for increased JunB expression. Selective inactivation of the type II receptors alters the TGF-beta response in a similar manner to the functional inactivation of pRB, suggesting a role for pRB in the type II, but not the type I, receptor pathway.

Summary Sucrose-positive derivatives of Escherichia coli K-12, containing the plasmid pUR400, and of Kiebsieiia pneumoniae hydrolyse intracellular sucrose 6-phosphate by means of an invertase into D-glucose 6phosphate and free D-fructose. The latter is phosphorylated by an ATP-dependent fruclokinase (gene scrK of an ser reguion) to D-fructose 6-phosphate. The lack of ScrK does not cause any visible phenotype in wildtype strains of both organisms. Using genes and enzymes normally involved in D-arabinitoi metabolism from E. coli C and K. pneumoniae, derivatives of E. coii K-12 vi/ere constructed which allowed the identification of scr/C mutations on conventional indicator plates. Cloning and sequencing of scrK from sucrose ptasmid pUR400 and from the chromosome of K. pneumoniae revealed an open reading frame of 924 bp in both cases — the equivalent of a peptide containing 307 amino acid residues {M, 39 and 34 kDa, respectively, on sodium dodecyl sulphate gels). The sequences showed overall identity among each other (69% identical residues) and to a kinase from Vibrio alginoiyticus (57%) also involved in sucrose metabolism, iower overall identity (39%) to a Dribose-kinase from E. coli, and local similarity to prokaryotic, and eukaryotic phosphofructokinases at the putative ATP-binding sites.

Two structurally related but different polypeptide growth factors, epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), exert their activities after interaction with a common cell-surface EGF/TGF-alpha-receptor. Comparative studies of the effects of both ligands have established that TGF-alpha is more potent than EGF in a variety of biological systems. This observation is not explained by differences in affinities of the ligands for the receptor, because the affinity-constants of both factors are very similar. We have compared the intracellular processing of ligand-receptor complexes using either EGF or TGF-alpha in two different cell systems. We found that TGF-alpha dissociates from the EGF/TGF-alpha-receptor at much higher pH than EGF, which may reflect the substantial difference in the calculated isoelectric points. After internalization, the intracellular TGF-alpha is more rapidly cleared than EGF, and a substantial portion of the released TGF-alpha represents undegraded TGF-alpha in contrast to the mostly degraded EGF. In addition, TGF-alpha did not induce a complete down-regulation of cell surface receptors, as observed with EGF, which is at least in part responsible for a much sooner recovery of the ligand-binding ability after down-regulation, in the case of TGF-alpha. These differences in processing of the ligand-receptor complexes may explain why TGF-alpha exerts quantitatively higher activities than EGF.

During the molecular analysis of a plasmid-coded sucrose metabolic pathway of enteric bacteria, a gene, scrY, was found whose product, ScrY, had all the properties of a bacterial porin (Schmid et al., 1988). Loss of this protein (Mr 58 kDa), localized in the outer membrane, led, as shown here, to an increase in the apparent Km for sucrose transport in whole cells from 10 microM in wild-type cells to 300 microM in mutant cells. This contrasts with the Km for sucrose phosphorylation as measured in membrane vesicles from mutant and wild-type cells, which remained unchanged at about 10 microM, and reflects the activity of the sucrose-specific Enzymell of the phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system (PTS) responsible for uptake through the inner membrane. Furthermore, the presence of ScrY restored growth on maltodextrins in cells devoid of LamB, thus complementing the lack of this maltoporin. The amino acid sequence deduced from the DNA sequence was determined for the plasmid-coded and the ScrY porin coded in the chromosome of Klebsiella pneumoniae. Both show high identity (86%) to each other, and to the channel domain of LamB, further corroborating the conclusion that they constitute porins.

Prognosis for patients suffering from malignant glioma has not substantially improved. Specific immunotherapy as a novel treatment concept critically depends on target antigens, which are highly overexpressed in the majority of gliomas, but the number of such antigens is still very limited. SOX2 was identified by screening an expression database for transcripts that are overexpressed in malignant glioma, but display minimal expression in normal tissues. Expression of SOX2 mRNA was further investigated in tumour and normal tissues by real-time PCR. Compared to cDNA from pooled normal brain, SOX2 was overexpressed in almost all (9 out of 10) malignant glioma samples, whereas expression in other, non-malignant tissues was almost negligible. SOX2 protein expression in glioma cell lines and tumour tissues was verified by Western blot and immunofluorescence. Immunohistochemistry demonstrated SOX2 protein expression in all malignant glioma tissues investigated ranging from 6 to 66% stained tumour cells. Human leucocyte antigen-A(*)0201-restricted SOX2-derived peptides were tested for the activation of glioma-reactive CD8+ cytotoxic T lymphocytes (CTLs). Specific CTLs were raised against the peptide TLMKKDKYTL and were capable of lysing glioma cells. The abundant and glioma-restricted overexpression of SOX2 and the generation of SOX2-specific and tumour-reactive CTLs may recommend this antigen as target for T-cell-based immunotherapy of glioma.