Viability of Glioblastoma Cells and Fibroblasts in the Presence of Imidazole-Containing Compounds.

The naturally occurring dipeptide carnosine (ß-alanyl-L-histidine) specifically attenuates tumor growth. Here, we ask whether other small imidazole-containing compounds also affect the viability of tumor cells without affecting non-malignant cells and whether the formation of histamine is involved. Patient-derived fibroblasts and glioblastoma cells were treated with carnosine, L-alanyl-L-histidine (LA-LH), ß-alanyl-L-alanine, L-histidine, histamine, imidazole, ß-alanine, and L-alanine. Cell viability was assessed by cell-based assays and microscopy. The intracellular release of L-histidine and formation of histamine was investigated by high-performance liquid chromatography coupled to mass spectrometry. Carnosine and LA-LH inhibited tumor cell growth with minor effects on fibroblasts, and L-histidine, histamine, and imidazole affected viability in both cell types. Compounds without the imidazole moiety did not diminish viability. In the presence of LA-LH but not in the presence of carnosine, a significant rise in intracellular amounts of histidine was detected in all cells. The formation of histamine was not detectable in the presence of carnosine, LA-LH, or histidine. In conclusion, the imidazole moiety of carnosine contributes to its anti-neoplastic effect, which is also seen in the presence of histidine and LA-LH. Despite the fact that histamine has a strong effect on cell viability, the formation of histamine is not responsible for the effects on the cell viability of carnosine, LA-LH, and histidine.

Tumor-stromal cross-talk modulating the therapeutic response in pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant solid tumor with a dismal prognosis. The stroma component makes up to 90% of the tumor mass and is thought to be one of the main reasons for the tumor's high chemoresistance. Cancer associated fibroblasts (CAFs) have previously been identified to be the key stromal players. This is the first time we provide detailed in vitro experiments investigating tumor-stromal interactions when exposed to three well-known chemotherapeutic agents. METHODS: Monocultures, indirect and direct co-cultures of two PDAC cell lines (AsPC and Panc-1) and six primary patients derived CAFs were treated with gemcitabine, nab-paclitaxel and the γ-secretase-inhibitor (GSI) DAPT. The cell viability of each component was measured with XTT. Finally, IL-6 concentrations of the supernatants were analyzed. RESULTS: On the contrary to PDAC cell lines, CAF monocultures hardly responded to any treatment which suggested that stroma (CAFs) itself is more resistant to standard chemo-treatments than the epithelial cancer cells. Moreover, only a weak chemotherapeutic response was observed in direct co-cultures of cancer cells with CAFs. A change in the morphology of direct co-cultures was accompanied with the chemoresistance. CAFs were observed to build cage-like structures around agglomerates of tumor cells. High levels of IL-6 were also associated with a reduced response to therapy. Indirect co-cultures make the tumor-stromal interaction more complex. CONCLUSIONS: CAFs are highly chemoresistant. Direct cell-cell contact and high levels of IL-6 correlate with a high chemoresistance.

Characterization of Pancreatic and Biliary Cancer Stem Cells in Patient-derived Tissue.

BACKGROUND/AIM: Pancreatic ductal adenocarcinoma (PDAC) and extrahepatic cholangio-carcinoma (eCC) represent two cancer entities with devastating prognoses. Despite recent progress in research and treatment, therapy remains challenging. Cancer stem cells (CSCs) have been shown to play an important role in metastasis and chemoresistance. Therefore, CSCs may play a promising role as a potential therapeutic target. MATERIALS AND METHODS: A total of 31 patients (23 PDAC, 8 eCC) were included in the study. CSCs were analyzed in a single-cell suspension of tumor samples via fluorescence-activated cell scanning (FACS) with a functional Hoechst 33342 staining as well as a cell surface marker staining of the CSC-panel (CD24, CD44 and EpCAM) and markers to identify fibroblasts, leukocytes and components of the notch signaling pathway. Furthermore, the potential presence of CSCs among primary cancer-associated fibroblasts (CAFs) was assessed using the same FACS-panel. RESULTS: We showed that CSCs are present in patient-derived dissociated tumor tissue. The functional and surface marker profile of CSC-detection did in fact correlate. The amount of CSCs was significantly correlated with tumor characteristics such as a higher UICC stadium and nodal invasion. CSCs were not restricted to the epithelial cell fraction in tumor tissues, which has been verified in independent analysis of primary cell cultures of CAFs. CONCLUSION: Our study confirms the in vivo presence of CSCs in PDAC and eCC, stating a clinical significance thereof and thus their plausibility as therapeutic targets. In addition, stem-like cells also seem to constitute a part of the CAFs.

Volume flow in the common carotid artery does not decrease postprandially.

BACKGROUND AND PURPOSE: A commonplace explanation for postprandial fatigue is the assumption of the redistribution of perfusion from the cerebral to the mesenterial territory. However, this assumption has never been scientifically proven. METHODS: Because approximately 70% of the blood flow in the common carotid artery (CCA) is directed to the internal carotid artery, this vessel can be seen as a major brain-supplying artery. Flow volume in the CCA can be measured by color M-mode duplex sonography. The authors investigated the flow volume rate in 20 healthy volunteers before and after the intake of a high-energy meal. Heart rate, blood pressure, and expiratory CO2 were also measured at both times. RESULTS: There was a significant (P = .001) increase in right, left, and net CCA flow volume postprandially (right: from 362.0 [interquartile range 315.5-410.5] to 401.5 [322.1-486.4] mL/min; left: from 384.5 [345.5-439.0] to 414.5 [357.9-527.7] mL/min; net: from 756.0 [683.0-822.5] to 832.4 [713.7-967.26] mL/min). This increase was paralleled by a statistically significant increase in heart rate from 66 (58-70) to 76 (63-84) bpm, but without substantial correlation (r = 0.28) with the volume flow changes. There was no correlation with any other tested parameter. CONCLUSIONS: The authors conclude that the assumption of global brain hypoperfusion in the postprandial state cannot serve as an explanation for postprandial fatigue.

Stage-adapted treatment of HIV-associated Hodgkin lymphoma: results of a prospective multicenter study.

PURPOSE: Although the outcome of patients with HIV-related Hodgkin lymphoma (HIV-HL) has markedly improved since the introduction of combined antiretroviral therapy, standard therapy is still poorly defined. This prospective study investigates a stage- and risk-adapted treatment strategy in patients with HIV-HL. PATIENTS AND METHODS: Patients with early favorable HIV-HL received two to four cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) followed by 30 Gy of involved-field (IF) radiation. In patients with early unfavorable HIV-HL, four cycles of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP baseline) or four cycles of ABVD + 30 Gy of IF radiation were administered. Six to eight cycles of BEACOPP baseline were given in patients with advanced-stage HIV-HL. In patients with advanced HIV infection, BEACOPP was replaced with ABVD. RESULTS: Of 108 patients (including eight female patients) included in the study, 23 (21%) had early favorable HL, 14 (13%) had early unfavorable HL, and 71 (66%) had advanced-stage HL. The median CD4 count at HL diagnosis was 240/µL. The complete remission rates for patients with early favorable, early unfavorable, and advanced-stage HL were 96%, 100%, and 86%, respectively. The 2-year progression-free survival of the entire study population was 91.7%. Eleven patients (11%) have died, and treatment-related mortality was 5.6%. The 2-year overall survival rate was 90.7% with no significant difference between early favorable (95.7%), early unfavorable (100%), and advanced-stage HL (86.8%). CONCLUSION: In patients with HIV-HL, stage- and risk-adapted treatment is feasible and effective. The prognosis for patients with HIV-HL may approach that of HIV-negative patients with HL.