Diagnostic accuracy of biopsy after neoadjuvant treatment for well-differentiated and dedifferentiated retroperitoneal liposarcoma.

PURPOSE: Accurate histopathological grading of percutaneous biopsies is essential to guide adequate management of patients with suspected retroperitoneal liposarcoma. In this regard, however, limited reliability has been described. Therefore, we conducted a retrospective study to assess the diagnostic accuracy in retroperitoneal soft tissue sarcomas and simultaneously investigate its impact on patients' survival. MATERIALS AND METHODS: Reports of an interdisciplinary sarcoma tumor board between 2012 and 2022 were systematically screened for patients with well-differentiated (WDLPS) and dedifferentiated retroperitoneal liposarcoma (DDLPS). Histopathological grading on pre-operative biopsy was correlated with corresponding postoperative histology. Additionally, patients' survival outcomes were examined. All analyses were performed in two subgroups: patients with primary surgery and patients with neoadjuvant treatment. RESULTS: A total of 82 patients met our inclusion criteria. Diagnostic accuracy of patients who underwent upfront resection (n = 32) was significantly inferior to patients with neoadjuvant treatment (n = 50) (66% versus 97% for WDLPS, p < 0.001; 59% versus 97% for DDLPS, p < 0.001). For patients with primary surgery, histopathological grading on biopsy and surgery was concordant in only 47% of cases. Sensitivity for detecting WDLPS was higher than for DDLPS (70% versus 41%). Higher histopathological grading in surgical specimens correlated with worse survival outcomes (p = 0.01). CONCLUSION: Histopathological grading of RPS may no longer be reliable after neoadjuvant treatment. The true accuracy of the percutaneous biopsy may need to be studied in patients who do not receive neoadjuvant treatment. Future biopsy strategies should aim to improve identification of DDLPS to inform patient management.

A clinically applicable gene expression-based score predicts resistance to induction treatment in acute myeloid leukemia.

Prediction of resistant disease at initial diagnosis of acute myeloid leukemia (AML) can be achieved with high accuracy using cytogenetic data and 29 gene expression markers (Predictive Score 29 Medical Research Council; PS29MRC). Our aim was to establish PS29MRC as a clinically usable assay by using the widely implemented NanoString platform and further validate the classifier in a more recently treated patient cohort. Analyses were performed on 351 patients with newly diagnosed AML intensively treated within the German AML Cooperative Group registry. As a continuous variable, PS29MRC performed best in predicting induction failure in comparison with previously published risk models. The classifier was strongly associated with overall survival. We were able to establish a previously defined cutoff that allows classifier dichotomization (PS29MRCdic). PS29MRCdic significantly identified induction failure with 59% sensitivity, 77% specificity, and 72% overall accuracy (odds ratio, 4.81; P = 4.15 × 10-10). PS29MRCdic was able to improve the European Leukemia Network 2017 (ELN-2017) risk classification within every category. The median overall survival with high PS29MRCdic was 1.8 years compared with 4.3 years for low-risk patients. In multivariate analysis including ELN-2017 and clinical and genetic markers, only age and PS29MRCdic were independent predictors of refractory disease. In patients aged ≥60 years, only PS29MRCdic remained as a significant variable. In summary, we confirmed PS29MRC as a valuable classifier to identify high-risk patients with AML. Risk classification can still be refined beyond ELN-2017, and predictive classifiers might facilitate clinical trials focusing on these high-risk patients with AML.

Frequency of Polyps and Adenocarcinoma in Colon Interposition After Esophagectomy in Adulthood - A Systematic Review.

BACKGROUND/AIM: Colon interposition counts among the most common techniques for reconstruction after esophagectomy. Availability of data on metachronous mucosal pathologies is weak. The aim of this review was to identify all reports on the development of metachronous adenoma and adenocarcinoma in colon interposition after esophagectomy in adulthood. MATERIALS AND METHODS: A comprehensive search was conducted in MEDLINE/PubMed, Science Direct, Cochrane Library, Bayerische Staatsbibliothek München. All studies reporting on patients who received colon interposition as substitute after esophagectomy in adulthood for benign and malignant reasons were included. RESULTS: Five retrospective studies were included, reporting on 1016 patients. Therein, no interval lesion was identified. One further study, which formally must be excluded for a misfit to inclusion criteria reports on three interval carcinomas within 365 patients. Because these lesions were the only ones found within a cohort analysis, results were supplementary reported in this review. Additionally, 31 case reports including 32 patients with benign (n=7) or malignant (n=25) findings were analyzed. Median age was 63.5 years (interval carcinoma) and 69 years (benign lesion). Benign and malignant lesions were diagnosed after a median of 8.5 years. CONCLUSION: Due to the rareness of respective cohort studies, the frequency of metachronous lesions cannot be calculated accurately. The estimated rate of interval carcinoma is 0-0.22%. Life-long endoscopic surveillance of patients with colon interposition is recommended.

International collaboration generates high quality clusters of pharmaceutical patents.

The worldwide active patent portfolio has nearly doubled in numbers and strength since 2000. The number of active pharmaceutical patent families has tripled in the same time period. The quantitative growth results mostly from a surge of patents from China, half of them classified in A61K36 ('medicinal preparations of undetermined constitution containing material from algae, lichens, fungi or plants'). High-quality patents exhibit a slower growth curve, and cluster within the three areas biologicals; heterocyclic compounds, and cancer drugs. However, the highest concentration of high-quality patents was found when selecting patents listing inventors from at least two out of the five most important countries of origin for pharmaceutical patents: China, EP countries, Japan, South Korea and the USA.

Patents as Early Indicators of Technology and Investment Trends: Analyzing the Microbiome Space as a Case Study.

The human microbiome is the collective of microbes living in symbiosis on and within humans. Modulating its composition and function has become an attractive means for the prevention and treatment of a variety of diseases including cancer. Since the initiation of the human microbiome project in 2007, the number of academic publications and active patent families around the microbiome has grown exponentially. Screening patent databases can be useful for the early detection and the tracking of new technology trends. However, it is not sufficient to assess portfolio sizes because emerging players with small but high-quality patent portfolios will be missed within the noise of large but low-quality portfolio owners. Here we used the consolidated database and software tool PatentSight to benchmark patent portfolios, and to analyze key patent owners and innovators in the microbiome space. Our study shows how in-depth patent analyses combining qualitative and quantitative parameters can identify actionable early indicators of technology and investment trends from large patent datasets.

Clinical Value of Contrast Enema Prior to Ileostomy Closure.

Purpose To determine the value of routine contrast enema of loop ileostomy before elective ileostomy closure regarding the influence on the clinical decision-making. Materials and Methods Retrospective analysis of contrast enemas at a tertiary care center between 2005 und 2011. Patients were divided into two groups: Group I with ileostomy reversal, group II without ileostomy closure. Patient-related parameters (underlying disease, operation method) and parameters based on the findings (stenosis, leakage of anastomosis, incontinence) were evaluated. Results Analyzing a total of 252 patients in 89 % (group I, n = 225) ileostomy closure was performed. In 15 % the radiologic report was the only diagnostic modality needed for therapy decision; in 36 % the contrast enema and one or more other diagnostic methods were decisive. In 36 % the radiological report of the contrast imaging was not relevant for decision at all. In 11 % (group II, n = 27) no ileostomy closure was performed. In this group in 11 % the radiological report of the contrast enema was the only decision factor for not performing the ileostomy reversal. In 26 % one or more examination was necessary. In 26 % the result of the contrast examination was not relevant. Conclusion The radiologic contrast imaging of loop ileostomy solely plays a minor role in complex surgical decision-making before planned reversal, but is important as first imaging method in detecting complications and often leads to additional examinations. Key points · Contrast enema of loop ileostomy before planned ileostomy closure is a frequently performed examination.. · There exist no general guidelines that give further recommendations on decision-making planning ileostomy closure.. · The radiologic contrast imaging of loop ileostomy solely plays a minor role in decision-making before planned reversal, but is important as first imaging method.. Citation Format · Goetz A, da Silva NP, Moser C et al. Clinical Value of Contrast Enema Prior to Ileostomy Closure. Fortschr Röntgenstr 2017; 189: 855 - 863.

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) does not affect proliferation, apoptosis, or angiogenesis as compared to standard liver resection for colorectal liver metastases.

BACKGROUND: ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) is a novel two-stage strategy to induce rapid hypertrophy of the future liver remnant (FLR) when patients are in danger of postoperative liver failure due to insufficient FLR. However, the effects of ALPPS on colorectal liver metastases (CRLM) are not clear so far. The aim of our study was to determine whether ALPPS induces proliferation, apoptosis, or vascularization compared to standard (one-stage) liver resection. METHODS: Six patients who underwent ALPPS were matched with 12 patients undergoing standard liver resection regarding characteristics of the metastases (size, number), time of appearance (syn-/metachronous), preoperative chemotherapy, primary tumor (localization, TNM stage, grading), and patient variables (gender, age). The largest resected metastasis was used for the analyses. Tissue was stained for tumor cell proliferation (Ki67), apoptosis (TUNEL, caspase-3), vascularization (CD31), and pericytes (αSMA). RESULTS: Vascularization (CD31; p = 0.149), proliferation (Mib-1; p = 0.244), and αSMA expression (p = 0.205) did not significantly differ between the two groups, although a trend towards less proliferation and αSMA expression was observed in patients undergoing ALPPS. Concerning apoptosis, caspase-3 staining showed significantly fewer apoptotic cells upon ALPPS (p < 0.0001), but this was not confirmed by TUNEL staining (p = 0.7344). CONCLUSIONS: ALPPS does not induce proliferation, apoptosis, or vascularization of CRLM when compared to standard liver resection.

Living-donor parathyroid allotransplantation for therapy-refractory postsurgical persistent hypoparathyroidism in a nontransplant recipient - three year results: a case report.

BACKGROUND: Therapy-refractory persistent hypoparathyroidism after extensive neck surgery is a rare but severe complication. Parathyroid allotransplantation may represent a definitive treatment option. CASE PRESENTATION: A 32-year old female was referred to our hospital with intractable persistent hypocalcemia after neck surgery for papillary thyroid cancer. Despite optimal medical treatment including calcium and vitamin D supplementation and even hormonal replacement therapy hypocalcemic symptoms failed to improve. The quality of life was considered very low. In light of the unsuccessful medical therapy and the young age of the patient parathyroid allotransplantation seemed an attractive treatment option to restore normal calcium homeostasis despite of the need for immunosuppressive therapy after the procedure. Therefore, we performed living-donor allotransplantation of two healthy parathyroid glands to the recipient's left forearm. The surgical intervention was successful. Neither the donor nor the recipient showed any complications. In the postoperative course clinical symptoms of hypocalcemia significantly improved whereas serum calcium and parathyroid hormone (PTH) levels progressively increased into the normal range. Former intense replacement therapy could be discontinued completely in a stepwise fashion. To date, nearly three years after transplantation, the patient remains asymptomatic with normal serum levels of calcium and PTH. CONCLUSION: Successful living-donor parathyroid allotransplantation for postsurgical hypoparathyroidism represents an innovative therapeutic strategy that could provide the definitive treatment in those patients in which the disease is therapy-refractory. The procedure can be justified even in nontransplant recipients. Retrieval of parathyroid glands from healthy donors is feasible and safe.

Targeting Fibroblast Growth Factor Receptor (FGFR) with BGJ398 in a Gastric Cancer Model.

AIM: To assess the efficacy of targeting fibroblast growth factor receptor (FGFR) with the pan-FGFR inhibitor BGJ398 in a gastric cancer (GC) model. MATERIALS AND METHODS: Expression of FGFRs was determined in GC cell lines (KKLS, MKN-45, TMK-1). Impact of the FGFR inhibitor BGJ398 on growth, motility, signaling, expression of transcription factors and secretion of vascular endothelial growth factor-A (VEGFA) was determined in vitro. Results were validated in subcutaneous tumor models. RESULTS: In vitro, FGFR inhibition was most effective in KKLS cells (high FGFR1, FGFR2IIIc, no FGFR2IIIb expression) with inhibition of growth, motility, signaling, c-MYC expression and VEGFA secretion. BGJ398 showed some activity in MKN-45 cells (intermediate FGFR1, high FGFR2IIIb, low FGFR2IIIc expression), while TMK-1 cells (low FGFR1, no FGFR2IIIb and FGFR2IIIc expression) did not respond. Results were confirmed in vivo with strongest efficacy on growth in KKLS tumors and only minor impairment of TMK-1 lesions. CONCLUSION: Efficacy of FGFR inhibition is dependent on FGFR1 and FGFR2IIIc expression in GC models.

Secretory Aspartyl Proteinases Cause Vaginitis and Can Mediate Vaginitis Caused by Candida albicans in Mice.

UNLABELLED: Vaginal inflammation (vaginitis) is the most common disease caused by the human-pathogenic fungus Candida albicans. Secretory aspartyl proteinases (Sap) are major virulence traits of C. albicans that have been suggested to play a role in vaginitis. To dissect the mechanisms by which Sap play this role, Sap2, a dominantly expressed member of the Sap family and a putative constituent of an anti-Candida vaccine, was used. Injection of full-length Sap2 into the mouse vagina caused local neutrophil influx and accumulation of the inflammasome-dependent interleukin-1ß (IL-1ß) but not of inflammasome-independent tumor necrosis factor alpha. Sap2 could be replaced by other Sap, while no inflammation was induced by the vaccine antigen, the N-terminal-truncated, enzymatically inactive tSap2. Anti-Sap2 antibodies, in particular Fab from a human combinatorial antibody library, inhibited or abolished the inflammatory response, provided the antibodies were able, like the Sap inhibitor Pepstatin A, to inhibit Sap enzyme activity. The same antibodies and Pepstatin A also inhibited neutrophil influx and cytokine production stimulated by C. albicans intravaginal injection, and a mutant strain lacking SAP1, SAP2, and SAP3 was unable to cause vaginal inflammation. Sap2 induced expression of activated caspase-1 in murine and human vaginal epithelial cells. Caspase-1 inhibition downregulated IL-1ß and IL-18 production by vaginal epithelial cells, and blockade of the IL-1ß receptor strongly reduced neutrophil influx. Overall, the data suggest that some Sap, particularly Sap2, are proinflammatory proteins in vivo and can mediate the inflammasome-dependent, acute inflammatory response of vaginal epithelial cells to C. albicans. These findings support the notion that vaccine-induced or passively administered anti-Sap antibodies could contribute to control vaginitis. IMPORTANCE: Candidal vaginitis is an acute inflammatory disease that affects many women of fertile age, with no definitive cure and, in its recurrent forms, causing true devastation of quality of life. Unraveling the fungal factors causing inflammation is important to be able to devise novel tools to fight the disease. In an experimental murine model, we have discovered that aspartyl proteinases, particularly Sap2, may cause the same inflammatory signs of vaginitis caused by the fungus and that anti-Sap antibodies and the protease inhibitor Pepstatin A almost equally inhibit Sap- and C. albicans-induced inflammation. Sap-induced vaginitis is an early event during vaginal infection, is uncoupled from fungal growth, and requires Sap and caspase-1 enzymatic activities to occur, suggesting that Sap or products of Sap activity activate an inflammasome sensor of epithelial cells. Our data support the notion that anti-Sap antibodies could help control the essence of candidal vaginitis, i.e., the inflammatory response.

Contrast-enhanced ultrasound (CEUS) detects effects of vascular disrupting therapy in an experimental model of gastric cancer.

OBJECTIVE: To assess the effects of vascular-disrupting agent (VDA)-based therapy including monitoring of therapeutic efficacy with contrast-enhanced ultrasound (CEUS) in a gastric cancer model. MATERIALS & METHODS: Gastric cancer cell lines and endothelial cells were used. Effects of the VDA ASA404 on cells were determined by MTT assays and Western blotting in vitro. Therapeutic efficacy of ASA404 was assessed in vivo in a subcutaneous mouse model in combination with paclitaxel. CEUS with TIC (time intensity curve) analyses was employed to measure tumor perfusion. Finally, tumor tissue was harvested and processed for histological work-up. RESULTS: In vitro, ASA404 impaired growth of ECs upon stimulation with conditioned media from gastric cancer cells. No direct effects on tumor cells were observed. In vivo treatment with ASA404 in combination with paclitaxel led to significant decrease of tumor microvascularization as determined by CEUS. Furthermore, combination of ASA404 with paclitaxel showed a significant inhibition of tumor growth which was paralleled by strong reduction of tumor cell proliferation and vessel area. CONCLUSION: VDA-based therapy in combination with paclitaxel, and therapy monitoring by CEUS, appears to be a promising strategy for gastric cancer.

Recent advances in mucosal immunization using virus-like particles.

Mucosal immunization offers the promises of eliciting a systemic and mucosal immune response, as well as enhanced patient compliance. Mucosal vaccination using defined antigens such as proteins and peptides requires delivery systems that combine good safety profiles with strong immunogenicity, which may be provided by virus-like particles (VLP). VLP are assembled from viral structural proteins and thus are devoid of any genetic material. They excel by mimicking natural pathogens, therefore providing antigen-protecting particulate nature, inherent immune-cell stimulatory mechanisms, and tissue-specific targeting depending on their parental virus. Nevertheless, despite of promising preclinical results, VLP remain rarely investigated in clinical studies. This review is intended to give an overview of obstacles and promises of VLP-based mucosal immunization as well as to identify strategies to further improve VLP while maintaining a good safety and tolerability profile.

STAT5b as molecular target in pancreatic cancer--inhibition of tumor growth, angiogenesis, and metastases.

The prognosis of patients suffering from pancreatic cancer is still poor and novel therapeutic options are urgently needed. Recently, the transcription factor signal transducer and activator of transcription 5b (STAT5b) was associated with tumor progression in human solid cancer. Hence, we assessed whether STAT5b might serve as an anticancer target in ductal pancreatic adenocarcinoma (DPAC). We found that nuclear expression of STAT5b can be detected in approximately 50% of DPAC. Blockade of STAT5b by stable shRNA-mediated knockdown showed no effects on tumor cell growth in vitro. However, inhibition of tumor cell motility was found even in response to stimulation with epidermal growth factor or interleukin-6. These findings were paralleled by a reduction of prometastatic and proangiogenic factors in vitro. Subsequent in vivo experiments revealed a strong growth inhibition on STAT5b blockade in subcutaneous and orthotopic models. These findings were paralleled by impaired tumor angiogenesis in vivo. In contrast to the subcutaneous model, the orthotopic model revealed a strong reduction of tumor cell proliferation that emphasizes the meaning of assessing targets in an appropriate microenvironment. Taken together, our results suggest that STAT5b might be a potential novel target for human DPAC.

Targeting HSP90 by the novel inhibitor NVP-AUY922 reduces growth and angiogenesis of pancreatic cancer.

AIM: To evaluate the impact of heat-shock protein 90 (HSP90) blockade by the novel inhibitor NVP-AUY922, on tumor growth and angiogenesis in pancreatic cancer. MATERIALS AND METHODS: Effects of NVP-AUY922 on signaling pathways were evaluated by western blotting. Cell motility of cancer cells, pericytes and endothelial cells was investigated in Boyden chambers. Impact of HSP90 blockade on pancreatic tumor growth and angiogenesis were studied in in vivo tumor models. RESULTS: NVP-AUY922 effectively inhibited cancer cell growth. Moreover, HSP90 inhibition potently interfered with multiple signaling pathways in cancer cells, as well as endothelial cells and pericytes, leading to significant reduction of pro-migratory and invasive properties of these cell types. In vivo, treatment with NVP-AUY922 significantly inhibited growth and vascularization of pancreatic cancer at doses far below the maximum tolerated dose. CONCLUSION: HSP90 blockade by the novel synthetic inhibitor NVP-AUY922 effectively reduces pancreatic cancer progression through direct effects on cancer cells, as well as on endothelial cells and pericytes.

Oncogenic MST1R activity in pancreatic and gastric cancer represents a valid target of HSP90 inhibitors.

AIM: To evaluate the effects of HSP90 blockade by EC154 on the oncogenic receptor tyrosine kinase macrophage-stimulating 1 receptor (MST1R) in gastric and pancreatic cancer. MATERIALS AND METHODS: Impact of EC154 on signaling pathways was investigated by western blotting. Cancer cell migration was evaluated in Boyden chambers. Transcriptional regulation of MST1R was examined by using promoter-luciferase reporter constructs. Effects on MST1R expression, and tumor growth were investigated in in vivo tumor models. RESULTS: MST1R was expressed by cancer cells without evidence of MST1R mutations. EC154 led to an effective inhibition of cancer cell growth, down-regulated MST1R, diminished its promoter activity, and disrupted oncogenic macrophage-stimulating protein 1 (MSP1) signaling. Moreover, pro-migratory activities of cancer cells were dramatically inhibited. In vivo, treatment with EC154 significantly reduced tumor growth, while MST1R expression was down-regulated. CONCLUSION: Wild-type MST1R is an HSP90 client protein that can be targeted in gastrointestinal cancer using HSP90 inhibitors.

Targeting FGFR/PDGFR/VEGFR impairs tumor growth, angiogenesis, and metastasis by effects on tumor cells, endothelial cells, and pericytes in pancreatic cancer.

Activation of receptor tyrosine kinases, such as fibroblast growth factor receptor (FGFR), platelet-derived growth factor receptor (PDGFR), and VEGF receptor (VEGFR), has been implicated in tumor progression and metastasis in human pancreatic cancer. In this study, we investigated the effects of TKI258, a tyrosine kinase inhibitor to FGFR, PDGFR, and VEGFR on pancreatic cancer cell lines (HPAF-II, BxPC-3, MiaPaCa2, and L3.6pl), endothelial cells, and vascular smooth muscle cells (VSMC). Results showed that treatment with TKI258 impaired activation of signaling intermediates in pancreatic cancer cells, endothelial cells, and VSMCs, even upon stimulation with FGF-1, FGF-2, VEGF-A, and PDGF-B. Furthermore, blockade of FGFR/PDGFR/VEGFR reduced survivin expression and improved activity of gemcitabine in MiaPaCa2 pancreatic cancer cells. In addition, motility of cancer cells, endothelial cells, and VSMCs was reduced upon treatment with TKI258. In vivo, therapy with TKI258 led to dose-dependent inhibition of subcutaneous (HPAF-II) and orthotopic (L3.6pl) tumor growth. Immunohistochemical analysis revealed effects on tumor cell proliferation [bromodeoxyuridine (BrdUrd)] and tumor vascularization (CD31). Moreover, lymph node metastases were significantly reduced in the orthotopic tumor model when treatment was initiated early with TKI258 (30 mg/kg/d). In established tumors, TKI258 (30 mg/kg/d) led to significant growth delay and improved survival in subcutaneous and orthotopic models, respectively. These data provide evidence that targeting FGFR/PDFGR/VEGFR with TKI258 may be effective in human pancreatic cancer and warrants further clinical evaluation.

Tumor development in murine ulcerative colitis depends on MyD88 signaling of colonic F4/80+CD11b(high)Gr1(low) macrophages.

Patients with prolonged ulcerative colitis (UC) frequently develop colorectal adenocarcinoma for reasons that are not fully clear. To analyze inflammation-associated colonic tumorigenesis, we developed a chronic form of oxazolone-induced colitis in mice that, similar to UC, was distinguished by the presence of IL-13-producing NKT cells. In this model, the induction of tumors using azoxymethane was accompanied by the coappearance of F4/80+CD11b(high)Gr1(low) M2 macrophages, cells that undergo polarization by IL-13 and are absent in tumors that lack high level IL-13 production. Importantly, this subset of macrophages was a source of tumor-promoting factors, including IL-6. Similar to dextran sodium sulfate-induced colitis, F4/80+CD11b(high)Gr1(intermediate) macrophages were present in the mouse model of chronic oxazolone-induced colitis and may influence tumor development through production of TGF-ß1, a cytokine that inhibits tumor immunosurveillance. Finally, while robust chronic oxazolone-induced colitis developed in myeloid differentiation primary response gene 88-deficient (Myd88-/-) mice, these mice did not support tumor development. The inhibition of tumor development in Myd88-/- mice correlated with cessation of IL-6 and TGF-ß1 production by M2 and F4/80+CD11b(high)Gr1(intermediate) macrophages, respectively, and was reversed by exogenous IL-6. These data show that an UC-like inflammation may facilitate tumor development by providing a milieu favoring development of MyD88-dependent tumor-supporting macrophages.

Transforming growth factor-beta 2 gene silencing with trabedersen (AP 12009) in pancreatic cancer.

Pancreatic cancer is one of the most aggressive human cancers with a 5-year survival rate of <5%. Overexpression of transforming growth factor-beta 2 (TGF-ß2) in pancreatic malignancies is suggested to be a pivotal factor for malignant progression by inducing immunosuppression, metastasis, angiogenesis and proliferation. Trabedersen (AP 12009) is a phosphorothioate antisense oligodeoxynucleotide specific for human TGF-ß2 mRNA and was successfully tested in a randomized, active-controlled phase IIb clinical study in patients with high-grade glioma. Here, we report on the antitumor activity of trabedersen in human pancreatic cancer cells and in an orthotopic xenograft mouse model of human metastatic pancreatic cancer. Trabedersen reduced TGF-ß2 secretion in human pancreatic cell lines with an IC50 in the low µM range without transfection reagent, clearly inhibited cell proliferation, and completely blocked migration of pancreatic cancer cells. Additionally, trabedersen reversed TGF-ß2-mediated immunosuppression of pancreatic cancer cells targeted by lymphokine activated killer (LAK) cells, resulting in considerably increased LAK cell-mediated cytotoxicity. Moreover, in an orthotopic mouse model of metastatic pancreatic cancer, intraperitoneal (i.p.) treatment with trabedersen significantly reduced tumor growth, lymph node metastasis and angiogenesis. These promising results warrant further clinical development of trabedersen.

Activating transcription factor-3 (ATF3) functions as a tumor suppressor in colon cancer and is up-regulated upon heat-shock protein 90 (Hsp90) inhibition.

BACKGROUND: Activating transcription factor-3 (ATF3) is involved in the complex process of cellular stress response. However, its exact role in cancer is discussed controversially because both tumor suppressive and oncogenic effects have been described. Here we followed-up on our previous observation that inhibition of Hsp90 may increase ATF3 expression and sought to determine the role of ATF3 in colon cancer. METHODS: Regulation of ATF3 was determined in cancer cells using signaling inhibitors and a heat-shock protein-90 (Hsp90) antagonist. Human HCT116 cancer cells were stably transfected with an ATF3-shRNA or a luciferase-shRNA expression plasmid and alterations in cell motility were assessed in migration assays. The impact of ATF3 down-regulation on cancer growth and metastasis were investigated in a subcutaneous tumor model, a model of hepatic tumor growth and in a model of peritoneal carcinomatosis. Human colon cancer tissues were analyzed for ATF3 expression. RESULTS: The results show that therapeutic Hsp90 inhibition substantially up-regulates the expression of ATF3 in various cancer cells, including colon, gastric and pancreatic cancer. This effect was evident both in vitro and in vivo. RNAi mediated knock-down of ATF3 in HCT116 colon cancer cells significantly increased cancer cell migration in vitro. Moreover, in xenogenic mouse models, ATF3 knock-down promoted subcutaneous tumor growth and hepatic metastasis, as well as peritoneal carcinomatosis. Importantly, ATF3 expression was lower in human colon cancer specimens, as compared to corresponding normal surrounding tissues, suggesting that ATF3 may represent a down-regulated tumor suppressor in colon cancer. CONCLUSION: In conclusion, ATF3 down-regulation in colon cancer promotes tumor growth and metastasis. Considering that blocking Hsp90 induces ATF3 expression, Hsp90 inhibition may represent a valid strategy to treat metastatic colon cancer by up-regulating this anti-metastatic transcription factor.