Down-regulation of RI alpha subunit of cAMP-dependent protein kinase induces growth inhibition of human mammary epithelial cells transformed by c-Ha-ras and c-erbB-2 proto-oncogenes.

MCF- 10A is a spontaneously immortalized, non-transformed human mammary epithelial cell line. We have recently obtained MCF- 10A clones (MCF- 1OA HE cells) that are transformed following over-expression of both a human point-mutated c-Ha-ras and the c-erbB-2 proto-oncogenes. Two isoforms of the cAMP-dependent protein kinase (cAK) have been described in mammalian cells. Enhanced levels of type-I cAK (cAKI) are generally found in tumor cells. To determine whether inhibition of cAKl expression may interfere with ras and erbB-2 oncogene-induced transformation of human mammary epithelial cells, we have tested the effects of 2 agents that specifically down-regulate cAKI, such as 8-chloro-cAMP and an anti-sense oligodeoxynucleotide targeted against the R1α regulatory subunit of cAKl on MCF-10A HE cells. Treatment of MCF-10A HE cells with 8-chloro-cAMP induces a dose-dependent growth inhibition under both monolayer and soft-agar growth conditions, that is correlated with an accumulation of MCF-10A HE cells in G0/G, phases of the cell cycle and a reduction of the number of cells in S phase. In contrast, 8-chloro-cAMP has no effect on MCF-10A cell growth. Furthermore, 8-chloro-cAMP treatment of MCF-10A HE cells induces a 4- to 6-fold reduction in p185erbB-2 expression and brings p21 ras expression to levels comparable to those found in MCF-10A cells. Treatment of MCF-10A HE cells with an Rlα anti-sense oligodeoxynucleotide determines a comparable inhibition of both anchorage-dependent and anchorage-independent cell growth. Our results suggest that cAKl may act as a mediator of ras and erbB-2 oncogene action in human breast cells and that interference with cAKl action provides a potential tool for inhibiting the growth-promoting effects of these oncogenes

Phase I-II study of sequential combination of XELOX and bevacizumab plus erlotinib (XELOX-TARAV) in first line colorectal patients:Run in phase I part

Methods: Chemonaive mCRC patients were treated with OX, 130 mg/m2 day 1 plus XEL, 1625 mg/m2/day days 1 to 14; B 7.5 mg/kg day 1; E, orally days 2 to 18 at 100 mg (I dose level) and 150 mg (II level), every 3 weeks. Treatment was administered for a maximum of 9 cycles or until PD or unacceptable toxicity (UT). The maximum tolerated dose (MTD) was defined as the dose level immediately preceding that in which dose-limiting toxicity (DLT) has been identified. DLT was the dose causing UT (defined with conventional NCI criteria) in ‡2 patients within a 3-6 patients cohort during the first cycle. Pharmacodynamic studies were conducted to evaluate tissue and circulating biologic factors. Results: To date 9 patients were enrolled. During the first cycle of therapy, according to the phase I objective definition, DLT was recorded in 1 patient at dose level I (diarrhea G3) and 2 patients at dose level II (diarrhea G3-4). Therefore, dose level II was defined as the DLT and 3 additional patients were treated at I dose level and no further UT was experienced. Overall, 43 complete cycles were administered (median 3; range 1-12). Overall toxicity is reported in the following table. Tumor shrinkage (5 pts) or stabilization (1 pt) were observed in 6/8 patients evaluable for response assessment. Conclusion: Diarrhea was responsible of DLT at II dose level (E 150 mg). E 100 mg is the recommended dose to be combined with chemotherapy and B for the Phase II part of the study. Pharmacodynamic correlative studies are ongoing

PRECLINICAL AND PHASE I STUDY OF OXALIPLATIN AND TOPOTECAN IN COMBINATION IN HUMAN CANCER.

BACKGROUND: DNA damage caused by platinum agents is frequently followed by induction of topoisomerase I, providing a rationale for use of platinum-based compounds with topoisomerase I inhibitors. MATERIALS AND METHODS: We studied the effect of a sequential schedule of oxaliplatin on day I and topotecan on days 2-5, in human colon and ovarian cancer cells in vitro, in nude mice bearing human cancer xenografts and finally in cancer patients in a phase I trial. RESULTS: We demonstrated a supra-additive effect of this combination on inhibition of colony formation and induction of apoptosis in vitro. We then demonstrated that the two agents in combination markedly inhibit tumor growth in nude mice. We translated these results into a clinical setting, conducting a phase I study in cancer patients with oxaliplatin 85 mg/m2 on day 1 and topotecan at doses escalating from 0.5 to 1.5 mg/m2 on days 2-5. Sixty cycles of treatment were administered to 18 patients affected prevalently by ovarian and colorectal cancer. Combination with topotecan 1.5 mg/m2 caused a dose-limiting toxicity. Therefore the maximum tolerated dose of topotecan was 1.25 mg/m2, at which six patients experienced a mild hematological and gastrointestinal toxicity. We also obtained evidence of clinical activity, particularly in ovarian cancer. CONCLUSIONS: Our results provide a solid biological and clinical rationale for a phase II trial at the recommended doses of oxaliplatin 85 mg/m2 and topotecan 1.25 mg/m2, possibly in ovarian cancer patients