The K- ras gene mutations were present in only one (1,5%) MGUS subject and in twenty (27,4%) MM ones. As expected, none of the control specimens analyzed manifested gene alterations (Table 3). In fact, it was observed a highly significant (p < 0.0001) difference between the controls and

MM or between MGUS and MM, while no significance learn more was found between controls and MGUS groups (p = 0.95) by means of a two by two comparison of the three groups (controls, MGUS and MM) concerning the distribution of K- ras gene mutation, Table 3 K- ras gene status and Ferrostatin-1 response to therapy Group K12- ras gene mutation/total (%) Positive therapy response (%) P Value     Mutant Wild type   Controls 0/75 (0) __ __ __ MGUS 1/66 (1.5) __ __ __ MM 20/73 (27.4) 26.9 58.3 0.01 Statistical significance for K12-ras gene mutation: Control vs MGUS p = 0.95, Control vs MM p = 0.0001, MGUS vs MM p < 0.0001, Positive therapy response: minor response and no change disease (see Methods). Interestingly, significant increases (P = 0.02) of serum bFGF levels were observed in patients showing K- ras gene mutation Blasticidin S clinical trial (median = 4.6 pg/ml; range = 1.2–19.6 pg/ml) as compared with those

in which the gene was in the wild type form (median = 2.2 pg/ml; range = 1.0–20.8 pg/ml). No statistically significant differences between K- ras gene status and serum factor concentrations were found for IGF-I or VEGF. MM response to Melphalan therapy Seventy-three MM patients showing or not K- ras gene mutations were analyzed for their response to therapy. As shown in Table 3, the presence of K- ras mutations was significantly associated with a lower response to Melphalan as compared with the wild type K- ras subjects (p = 0.015). A statistically not significant trend (p = 0.07) was also observed for the serum bFGF concentrations when comparing responders (mean = 1.9 pg/ml; range = 1.2–20.8 pg/ml) with non responders (mean = 3.8 pg/ml; range = 1.3–19.6 pg/ml). In an attempt to find a link between the response to therapy (yes/not), K- ras gene status (mutant/wild type) and the cytokine level (greater or lower than cut-off), we acetylcholine could only confirm the strong influence of K- ras gene status rather

than the level of the four different cytokines in determining the therapy response of MM patients (data not shown). Monitoring of two MM patients for Monoclonal component concentration and serum IGF-1 levels Several patients were followed up during therapy. Figure 1 shows two of them presenting at least six/seven observation times in which consecutive serum samples from the time of diagnosis until death were analyzed. The first patient (panel A) had a high serum IGF-I (165 ng/ml) level at diagnosis. He showed a minor response to treatment for a least 15 months, with a 26% fall in serum M-protein concentration and a concomitant slight reduction of IGF-I amounts. Then new cycles of therapy were administered because of tumour progression.