Synergistic cytotoxic activity of treosulfan and gemcitabine in pancreatic cancer cell lines.

BACKGROUND: Treatment for advanced pancreatic cancer is still very unsatisfactory. Treosulfan is an alkylating agent used for conventional, as well as high-dose chemotherapy regimens, whereby plasma concentrations over 500 µg/ml can be achieved. We investigated the effects of treosulfan on pancreatic cancer cell lines. MATERIALS AND METHODS: Using Panc-1, MIA PaCa-2 and Capan-2 cell lines, we investigated the in vitro cytotoxicity of treosulfan-alone and in combination with gemcitabine, 5-fluorouracil or irradiation. RESULTS: Treosulfan was potently cytotoxic against all pancreatic cancer cell lines at all concentrations (1-100 µg/ml). Combination of treosulfan and gemcitabine revealed strong synergistic effects independent of the sequence of drug administration. Similarly, synergism was observed with irradiation. Combination of treosulfan and 5-fluorouracil revealed antagonism. CONCLUSION: Treosulfan effectively kills pancreatic carcinoma cells in vitro and has synergistic activity in combination with gemcitabine and irradiation. These results warrant further investigation of treosulfan in the treatment of pancreatic cancer.

PTEN deletion is rare but often homogeneous in gastric cancer.

BACKGROUND AND AIM: Gastric carcinoma is the second most frequent cause of cancer-related death worldwide. As PTEN is a potential modifier of tumour response to trastuzumab, a recently approved therapy in metastatic HER2 positive gastric cancer, the existence of PTEN deletions in primary gastric cancer was investigated. METHODS: 230 primary gastric cancers were analysed in a tissue microarray format by dual labelling fluorescence in situ hybridisation for PTEN deletion. HER2 analysis was also performed. To study PTEN deletion heterogeneity, all available large tissue sections from primary cancer and corresponding metastases were analysed in seven patients. RESULTS: Eight of 180 interpretable primary gastric cancer spots showed PTEN deletions (4.4%), including seven hemizygous and one homozygous deletion. PTEN deletion was correlated with nodal (8 of 122 cases (6.6%); p=0.041) and distant metastases (4 of 19 (21.1%); p<0.001). Large section validation showed a homogeneous distribution of PTEN deletion. HER2 positivity was seen in one PTEN deleted case. CONCLUSION: Genomic PTEN deletion is a rare event in gastric adenocarcinoma but correlates with metastatic disease. The homogeneous distribution pattern indicates that this alteration occurs early in tumour development.

The GNAS1 T393C single nucleotide polymorphism predicts the natural postoperative course of complete resected esophageal cancer.

BACKGROUND: Genetic variations in cancer patients may serve as important prognostic indicators of clinical outcome. The GNAS1 T393C single nucleotide polymorphism (SNP) diversely correlates with the clinical outcome in cancer. The aim of this study was to evaluate the potential prognostic value of T393C-SNP in complete resected only surgically treated esophageal cancer (EC). METHODS: Genomic DNA was extracted from peripheral blood leucocytes of 190 patients who underwent only complete surgical resection for EC. T393C-SNP was correlated with clinic-pathological parameters, tumor cell dissemination in bone marrow (DTC) and clinical outcome. RESULTS: T-allele carriers had more advanced disease due to presence of lymph node metastasis (P < 0.0001) and DTC (P = 0.01) and higher recurrence rate (P = 0.01) compared to CC genotype. The disease-free (P < 0.001) and overall survival (P < 0.001) was better in CC compared to TT and TC patients. In the multivariate Cox regression disease-stage adjusted analysis the T393C-SNP was identified as a strong independent prognostic factor for recurrence (hazard ratio 1.8, P = 0.01) and survival (hazard ratio 2.5, P < 0.001) in EC patients. CONCLUSION: Determination of T393C-SNP preoperatively will allow allocation of EC patients into different risk profiles which may help to stratify patients eligible for neoadjuvant and or adjuvant therapy.

Complement-dependent and complement-independent cytotoxicity of polyclonal antithymocyte globulins in chronic lymphocytic leukemia.

OBJECTIVE: Despite important progress in its management, chronic lymphocytic leukemia (CLL) remains incurable with standard therapies. Allogeneic stem cell transplantation (SCT) is a potentially curative therapy for patients with CLL. Polyclonal antithymocyte (or anti-T-cell) globulins (ATGs) are used for conditioning in allogeneic SCT mainly due to their anti-T-cell activity. ATGs however, contain antibodies targeting antigens expressed on various hematopoietic cells including B cells. METHODS: We assessed anti-CLL activity of two commercially available ATG preparations at clinically relevant concentrations (10-100 microg/ml) in CLL samples from 16 patients. Cytotoxicity was determined by staining with 7-amino-actinomycin D (7-AAD), annexin V and flow cytometry. RESULTS: Both ATG preparations induced marked complement-independent dose-dependent cytotoxicity in all samples. Addition of complement strongly enhanced the cytotoxic effect of both ATG preparations significantly. ATG-induced complement-dependent cytotoxicity (CDC) was at least as high as that observed with Alemtuzumab. Both ATGs enhanced the cytotoxic effect of Fludarabine. CONCLUSION: ATG is an effective agent against CLL in vitro. We suggest that this potential be taken into consideration when developing stem cell transplantation protocols for patients with CLL.