Serous ovarian cancer signaling pathways.

Ovarian cancer is the most lethal malignancy of the female genital tract, mainly due to the failure of early diagnosis and the limitations posed by the conventional chemotherapies. Current research has focused in the study of cascades of various cellular molecular reactions, known as signaling pathways. In this review article, authors try to describe the current knowledge regarding the signaling pathways that influence multiple cellular processes in serous ovarian cancer and especially the pathogenesis. Thorough understanding of the precise role of these pathways can lead to the development of new and more effective targeted therapies as well as novel biomarkers in ovarian cancer.

Effects of a dental adhesive on cell cycle regulatory proteins.

Dental bonding agents may affect the cell cycle patterns and induce cell cycle arrest by blocking its progression. This study tested the cell cycle effects through cyclin-dependent kinase (cdc2) and Rb phosphorylation. Human lung fibroblasts (MRC5) were used for the experiments. The bonding agent tested was the total-etch XP bond. Extracts of the bonding agent were prepared and serial dilutions were tested. The effects of the bonding agent on cell survival, proliferation and DNA synthesis were tested by the SRB and BrdU assays. Analysis of cell cycle distribution was performed by flow cytometry. XP bond exhibited strong inhibition of DNA synthesis and after 48 h of exposure cells were accumulated in the G2/M phase. Cells exposed to the half maximal cell growth inhibitory concentration (IC50) showed an increase in cdc2 kinase and Rb phosphorylation. The results most likely indicate mutagenic effect of the tested agent.

Paclitaxel and bevacizumab as first line combined treatment in patients with metastatic breast cancer: the Hellenic Cooperative Oncology Group experience with biological marker evaluation.

BACKGROUND: Randomized studies have shown that bevacizumab combined with taxane-based regimens increases response rates and prolongs progression-free survival (PFS) of patients with metastatic breast cancer (MBC). However predictive or prognostic biological markers that identify the appropriate target population, thus improving the cost-effectiveness ratio of this treatment, are still needed. PATIENTS AND METHODS: Retrospectively, 124 patients with MBC treated either with paclitaxel 90 mg/m² weekly x12 plus bevacizumab 10 µg/kg every 2 weeks or 15 µg/kg every 3 weeks (85 patients) or paclitaxel 175 mg/m² plus bevacizumab 15 µg/kg every 3 weeks for 6 cycles (36 patients) were identified. Additionally, the prognostic significance of a panel of key biological markers was evaluated centrally by immunohistochemistry (IHC) in 88 evaluable patients. RESULTS: More than two thirds of the patients completed chemotherapy, as planned. The response rate was almost identical (55.3% vs. 55.6%) in the patients treated with weekly or 3-weekly paclitaxel, respectively. After a median follow-up time of 23 months, the median PFS of the study population was 13 months, while median survival had not yet been reached. Common severe adverse events were neutropenia (33%), neuropathy (18.6%) and metabolic disturbances (17.6%). The incidence of hypertension of all grades was 28.1%. High expression of vascular endothelial growth factor (VEGF) receptor 3 (VEGFR3) was associated with clinical response, while high expression of VEGFR1 was associated with poor survival. CONCLUSION: The safety and activity of the combination of bevacizumab with paclitaxel given either weekly or 3-weekly in patients with MBC is confirmed.

Brain natriuretic peptide precursor (NT-pro-BNP) levels predict for clinical benefit to sunitinib treatment in patients with metastatic renal cell carcinoma.

BACKGROUND: Sunitinib is an oral, multitargeted tyrosine kinase inhibitor that has been approved for the treatment of metastatic renal cell carcinoma. Although the majority of sunitinib-treated patients receive a clinical benefit, almost a third of the patients will not respond. Currently there is no available marker that can predict for response in these patients. METHODS: We estimated the plasma levels of NT-pro-BNP (the N-terminal precursor of brain natriuretic peptide) in 36 patients that were treated with sunitinib for metastatic clear-cell renal carcinoma. RESULTS: From the 36 patients, 9 had progressive disease and 27 obtained a clinical benefit (objective response or disease stabilization). Increases in plasma NT-pro-BNP were strongly correlated to clinical outcome. Patients with disease progression increased plasma BNP at statistically significant higher levels than patients that obtained a clinical benefit, and this was evident from the first 15 days of treatment (a three-fold increase in patients with progressive disease compared to stable NT-pro-BNP levels in patients with clinical benefit, p < 0.0001). Median progression-free survival was 12.0 months in patients with less than 1.5 fold increases (n = 22) and 3.9 months in patients with more than 1.5 fold increases in plasma NT-pro-BNP (n = 13) (log-rank test, p = 0.001). CONCLUSIONS: This is the first time that a potential "surrogate marker" has been reported with such a clear correlation to clinical benefit at an early time of treatment. Due to the relative small number of accessed patients, this observation needs to be further addressed on larger cohorts. More analyses, including multivariate analyses are needed before such an observation can be used in clinical practice.

Synthesis, Structure, and Antiproliferative Activity of Three Gallium(III) Azole Complexes.

As part of our interest into the bioinorganic chemistry of gallium, gallium(III) complexes of the azole ligands 2,1,3-benzothiadiazole (btd), 1,2,3-benzotriazole (btaH), and 1-methyl-4,5-diphenylimidazole (L) have been isolated. Reaction of btaH or btd with GaBr(3) or GaCl(3) resulted in the mononuclear complexes [GaBr(3)(btaH)(2)] (1) and [GaCl(3)(btd)(2)] (2), respectively, while treatment of GaCl(3) with L resulted in the anionic complex (LH)(2)[GaCl(4)] (3). All three complexes were characterized by single-crystal X-ray crystallography and IR spectroscopy, while their antiproliferative activities were investigated against a series of human and mouse cancer cell lines.

Sunitinib treatment for patients with clear-cell metastatic renal cell carcinoma: clinical outcomes and plasma angiogenesis markers.

BACKGROUND: Sunitinib is a protein tyrosine kinase-inhibitor targeting VEGFR, c-kit and PDGFR. It has been approved for the treatment of metastatic renal-cell carcinoma and gastrointestinal stromal tumors. Although it has been shown to prolong disease-free and overall survival in renal-cell carcinoma patients, only 70% of the treated population receive a clinical benefit (CB) from the treatment. Markers that could predict clinical benefit to sunitinib would be an important aid in monitoring and following their treatment. We assessed the outcome and plasma proangiogenic factors in patients with metastatic renal cell carcinoma (mRCC) treated with sunitinib in our institution. METHODS: We have treated 42 patients with metastatic clear-cell renal carcinoma with sunitinib. Plasma concentrations of VEGF-A, sVEGFR2 and PDGF were determined by ELISA. RESULTS: At the time of analysis 39 patients were evaluable for response and 30 patients had obtained a clinical benefit (CB). Median progression-free survival was 268 days (8.93 months) and median overall survival was 487 days (16.23 months). Interestingly, disease stabilization or objective response resulted in comparable overall survival. Most treatment-related adverse events were of mild-to-moderate intensity with one treatment-related death. Plasma sVEGFR2 and PDGF levels had no predictive value. Fold-increase in plasma VEGF was significantly lower in patients that obtained a CB as compared to patients that progressed after two cycles of treatment. Plasma VEGF did not increase in patients with initial CB at the time of progression. CONCLUSION: Sunitinib showed substantial activity in mRCC. Disease stabilization or objective response resulted in comparable overall survival and both outcomes should be considered positive. Fold-increase in plasma VEGF predicts for CB and could be a candidate marker. Progression after initial CB is not associated with elevated plasma VEGF, implying a different mechanism of resistance.

Effects of dentin bonding agents on the cell cycle of fibroblasts.

The aim of this study was to evaluate the effects of 3 dentin bonding agents on cell survival and proliferation and on cell cycle progression of cultured cells. The experiments were performed on RPC-C2A and L929 cells. Specimens of the 3 dentin bonding agents (Clearfil Tri-S, AdheSE, and XP BOND) were placed in culture medium, and the extraction media were applied to cells as experimental material. The effect of the bonding materials on cell survival and proliferation was assessed by a modified sulforhodamine B staining assay, and the effect on DNA synthesis was assessed by bromodeoxyuridine uptake. Flow cytometry was used for cell cycle analysis. Cell viability and proliferation decreased in a dose-dependent manner after exposure of cells to the tested materials. XP BOND expressed the highest activity of all tested bonding agents (P < .05). The self-etch bonding agents tested did not produce any significant effects on cell cycle distribution. However, exposure of cells to the total-etch agent XP BOND induced a G(2)-phase arrest in both cell lines, and this effect was more evident in L929 cells than in RPC-C2A cells.

Synergism of Toll-like receptor-induced interleukin-12p70 secretion by monocyte-derived dendritic cells is mediated through p38 MAPK and lowers the threshold of T-helper cell type 1 responses.

Toll-like receptors (TLRs) recognise specific molecular signatures of pathogens and trigger antimicrobial defence responses. Thereby, two independent signalling pathways can be distinguished: The inflammatory signalling pathway acting via the adapter molecule MyD88, leading to the activation of nuclear factor-kappaB (NF-kappaB) and mitogen activated protein kinases (MAPK) such as SAPK/JNK and p38 MAPK and the interferon (IFN) dependent pathway that signals via TRIF and results in the production of IFN-alpha/beta. Several evolutionarily conserved molecular patterns are expressed by pathogens, leading to the question if concerted targeting of different TLRs may induce exaggerated immune responses by signalling via both TLR pathways. Here we report that monocyte-derived dendritic cells (MoDCs) combine and integrate signals received via the IFN-dependent pathway by engagement of TLR3 (poly I:C) and activation of TRIF with the MyD88-dependent pathway by ligation of TLR2 (PGN), TLR2/TLR6 (zymosan) and TLR5 (flagellin). The generally low IL-12p70 inducers resulted in combination of both pathways in cytokine levels similar to LPS, which acts via TLR4 and induces recruitment of MyD88/Tirap and TRIF/TRAM adapter proteins. The combination of TLR3 (poly I:C) or TLR4 (LPS) engagement with TLR8 (R848) ligation induced synergistic effects on cytokine production with a boost especially in IL-12p70 secretion. SB203580, a specific p38 MAPK inhibitor, completely blocked TLR ligand mediated IL-12p70 secretion, whereby specific inhibitors for SAPK/JNK (SP600125) and NF-kappaB (PDTC) only repressed partially the IL-12p70 secretion. Enhanced phosphorylation in poly I:C and R848 activated MoDCs revealed the critical contribution of p38 MAPK in synergistically induced IL-12p70 induction. Further investigation of primary and recall CD8+ T cell responses to the MUC(12-20) M1.2 peptide LLLLTVLTV and the influenza A virus matrix(58-66) peptide GILGFVFTL proved that synergistically activated MoDCs were superior compared with LPS or R848 alone. The results indicate that dendritic cells process, combine and integrate signals delivered by pathogens to launch effective adaptive immune responses.

Expression of the HER family mRNA in breast cancer tissue and association with cell cycle inhibitors p21(waf1) and p27(kip1).

BACKGROUND: The HER family of the receptor tyrosine kinases epidermal growth factor receptor (EGFR), HER2, HER3 and HER4 are involved in the pathogenesis of many human malignancies. Although there is extensive literature on the expression of single HER-2 and EGFR receptors in breast cancer, little is known concerning the simultaneous expression at the mRNA level of these four receptors in human breast tissue and their influence in downstream signaling pathways that control cell cycle and proliferation. MATERIALS AND METHODS: The mRNA expression pattern of the four HER-receptors has been investigated and correlated with the expression of the cyclin-dependent kinase (CDK) inhibitors p21(Waf1) and p27(Kip1) in 67 breast cancer specimens. RESULTS: A positive correlation between HER-3 and HER-4 mRNA levels and a negative correlation between HER-2 and HER-3 was found. Compared to normal breast tissue, all four receptors were overexpressed in breast tumors and the strongest overexpression was found for HER-3 (p = 0.001). HER-4 expression was inversely related to histopathological grading (HPG), suggesting that elevated HER-4 mRNA expressions could be a biological marker of a more differentiated phenotype. The expression of p21(Waf1) protein was higher in HER-2-negative tumors, compared to HER-2-positive breast carcinomas. Compared to normal breast tissue, p21delta, the 19 kDa degraded form of p21 protein, was markedly expressed in breast cancer (p < 0.001). Conversely, p27(Kip1) was positively associated with HER-2 receptor and inversely associated with HER-3. CONCLUSION: The HER family members are overexpressed in breast cancer. Complex patterns of HER family expression were observed and the effect on cell cycle regulation was dependent on that pattern.

Synergistic effects of protein tyrosine kinase inhibitor genistein with camptothecins against three cell lines in vitro.

Genistein, a natural isoflavone product has been shown to induce cellular death and increase the apoptotic cell death induced by several DNA-damaging stimuli. We have explored the combined effect of genistein and camptothecins against three cell lines, HeLa (cervical cancer), OAW-42 (ovarian cancer) and L929 (normal fibroblasts). Combined effect was estimated in 96-well plates using the SRB method and median-effect analysis. Addition of genistein synergistically increased the antiproliferative affect of camptothecins, inhibiting the camptothecin-induced G2/M arrest and increasing the apoptotic cell population. In HeLa cells, genistein inhibited CDK1 phosphorylation after irinotecan treatment. Thus, abrogation of the G2/M checkpoint control by genistein may be a useful maneuver to increase cytotoxicity of agents that damage DNA and inhibit cell-cycle progression in the G2/M boundary.

The association of p53 mutations and p53 codon 72, Her 2 codon 655 and MTHFR C677T polymorphisms with breast cancer in Northern Greece.

The aim of this study was to explore a possible association between p53 codon 72, Her 2 codon 655 and MTHFR C677T polymorphisms and breast cancer in Northern Greece. We examined 42 women with breast cancer and 51 controls. A total of 42 women with breast cancer as well as healthy controls were investigated and results showed that p53 codon 72 polymorphism is statistically significantly associated with breast cancer (OR for Arg/Arg to non-Arg/Arg was 6.66, P = 0.0001 at 95% CI 2.63-16.9), but not Her 2 and MTHFR polymorphisms are associated with breast cancer (OR for Ile/Ile to non-Ile/Ile was 1.33, P = 0.54 at 95% CI 0.52-3.38 and OR for T/T versus non-T/T was 1.07, P = 0.89 at 95% CI 0.35-3.25). All subjects were examined for p53 exons 5-8 mutations. Three novel sequence variations in exons 7 and 8 of TP53 gene were found in three patients. One of them induces an amino acid change at Ser 241Gly, the second is a silent mutation Gly244Gly, and the third one results in a premature stop codon 294 (Glu294stop) and a truncated p53 protein.

Antiproliferative effect of mineral trioxide aggregate, zinc oxide-eugenol cement, and glass-ionomer cement against three fibroblastic cell lines.

An important requirement for dental materials placed in direct contact with living tissues is biocompatibility. The purpose of this study was to evaluate the antiproliferative activity of three dental materials (mineral trioxide aggregate, zinc oxide-eugenol cement, and glass-ionomer cement) against a panel of established fibroblastic cell lines (L929, BHK21/C13, and RPC-C2A). The materials were prepared according to the manufacturer's instructions and were tested in insert wells for 12, 24, and 48 h. Cell number fraction was estimated by the sulforhodamine-B assay, in reference to controls. The degree of antiproliferative effect in ascending order was mineral trioxide aggregate, glass-ionomer cement, and zinc oxide-eugenol cement in all cell lines tested.