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Meeting Abstract : 27. Deutscher Krebskongress. Berlin, 22.-26.03.2006.
Docetaxel, Adriamycin, Cyclophosphamide (TAC) is considered today as one treatment option for patients with node-positive primary breast cancer. However, treatment is associated with anaemia grade 1-4 (2-4) in up to 95% (36%) of patients. We prospectively investigated the use of a primary prophylaxis with Darbepoetin alfa once every 3 weeks in 35 patients receiving six to eight cycles of TAC as neoadjuvant treatment for breast cancer. Darbepoetin treatment started on day 1 of a TAC cycle if haemoglobin (Hb) was ≤ 14.0 g/dl. Dosage was adapted to 9 µg/kg if Hb was ≤ 13.0 g/dl on day 21 of the previous cycle, to 4.5 µg/kg if Hb was between 13.0 and 14.0 g/dl and was discontinued if Hb increased to ≥ 14 g/dl. The primary aim was to prevent Hb levels ≤ 12 g/dl before surgery. During 112 (50.2%) and 93 (41.7%) of 223 cycles, 4.5 µg/kg and 9 µg/kg Darbepoetin were given, respectively. Dosage was decreased from 9 to 4.5 µg/kg in 21 (60%) patients and 28 (12.4%) cycles. Treatment was discontinued due to Hb > 14.0 g/dl in 12 (34.3%) patients and 13 (5.4%) cycles. Hb level on day 21 of the last cycle was ≤ 12.0 g/dl in 4 (11.4%) patients. Eighteen (51.4%) patients during 36 (16.1%) cycles showed Hb levels ≤ 12 g/dl throughout treatment. No NCI-CTC grade 2 to 4 anaemia was observed. Symptoms of fatigue (FACT-AN) decreased slightly throughout treatment. Anaemia during TAC chemotherapy can be avoided by a single injection of Darbepoetin alfa every 3 weeks.
Objective: Establishment of an immunocompetent mouse model representing the typical progressive stages observed in malignant human gliomas for the in vivo evaluation of novel target-specific regimens.
Methods: Isolated clones from tumours that arose spontaneously in GFAP-v-src transgenic mice were used to develop a transplantable brain tumour model in syngeneic B6C3F1 mice. STAT3 protein was knocked down by infection of tumour cells with replication-defective lentivirus encoding STAT3-siRNA. Apoptosis is designed to be induced by soluble recombinant TRAIL + chemical Bcl-2/Bcl-xL inhibitors.
Results: Striatal implantation of 105 mouse tumour cells resulted in the robust development of microscopically (2 – 3 mm) infiltrating malignant gliomas. Immunohistochemically, the gliomas displayed the astroglial marker GFAP and the oncogenic form of STAT3 (Tyr-705-phosphorylated) which is found in many malignancies including gliomas. Phosphorylated STAT3 was particularly prominent in the nucleus but was also found at the plasma membrane of peripherally infiltrating glioma cells. To evaluate the role of STAT3 in tumour progression, we stably expressed siRNA against STAT3 in several murine glioma cell lines. The effect of STAT3 depletion on proliferation, invasion and survival will be first assessed in vitro and subsequently after transplantation in vivo. Upstream and downstream components of the STAT3 signalling pathway as well as possible non-specific side effects of STAT3-siRNA expression after lentiviral infection will be examined, too.
Conclusions: Its high rate of engraftment, its similarity to the malignant glioma of origin, and its rapid locally invasive growth should make this murine model useful in testing novel therapies for malignant gliomas.