Search

The social work Grand Challenge to Promote Smart Decarceration's aim is to address the high rates of incarceration in the United States.Yet very little is known about criminal justice practitioners in the U.S.In this exploratory study. Practitioners in correctional facilities (Findings include the need for people who are incarcerated to have access to treatment for substance use, behavioral/mental health, and trauma-related issues. In addition, they reported the need for service coordination with agencies based in their home communities. Furthermore, the participants reported that they need more training and support on these topics in order to provide effective services to their clients.Implications for practice, research, and policy are discussed, including strategies to address all levels of primary, secondary, and tertiary prevention.

Meccanismi di resistenza ai farmaci antitumorali.

Farmaci antimicrotubulari

What is known and objective Mebendazole (MBZ) is a broad-spectrum antihelminthic agent of the benzimidazole type. Although MBZ has been reported to cause hepatic injury, case reports of severe hepatic injury are very rare. We report a case of severe hepatitis after administration of MBZ in a patient with Gilbert's syndrome affected by pinworms infestation. Case summary Differently from other cases of hepatitis due to MBZ reported in the scientific literature, our patient received standard doses of MBZ for a short period of time. After 18 days from the start of therapy, he developed hepatomegaly, and increases in hepatic enzymes and bilirubin. Hepatic enzymes returned to normal over the following 5 weeks. What is new and conclusion This is the first case report of important liver injury after administration of MBZ in a patient with Gilbert's syndrome. We suspected that a diminished hepatic glucuronidation of MBZ due to the reduced activity of the glucuronosyltransferase enzyme in our patient could have caused an increase in unconjugated toxic metabolites of MBZ and the consequent liver damage.

STAT5 is a transcription factor, a member of the STAT family of signaling proteins. STAT5 is involved in many types of cancer, including chronic myelogenous leukemia (CML), in which this protein is found constitutively activated as a consequence of BCR-ABL expression. The neuroleptic drug pimozide was recently reported to act as an inhibitor of STAT5 phosphorylation and is capable of inducing apoptosis in CML cells in vitro. Our research group has synthesized simple derivatives of pimozide with cytotoxic activity and that are able to decrease the levels of phosphorylated STAT5. In this work we continued the search for novel STAT5 inhibitors, synthesizing compounds in which the benzoimidazolinone ring of pimozide is either maintained or modified, in order to obtain further structure–activity relationship information for this class of STAT5 inhibitors. Two compounds of the series showed potent cytotoxic activity against BCR-ABL-positive and pSTAT5-overexpressing K562 cells and were able to markedly decrease the levels of phosphorylated STAT5.

The JAK-STAT pathway is an important physiologic regulator of different cellular functions including proliferation, apoptosis, differentiation, and immunological responses. Out of six different STAT proteins, STAT5 plays its main role in hematopoiesis and constitutive STAT5 activation seems to be a key event in the pathogenesis of several hematological malignancies. This has led many researchers to develop compounds capable of inhibiting STAT5 activation or interfering with its functions. Several anti-STAT5 molecules have shown potent STAT5 inhibitory activity in vitro. However, compared to the large amount of clinical studies with JAK inhibitors that are currently widely used in the clinics to treat myeloproliferative disorders, the clinical trials with STAT5 inhibitors are very limited. At present, a few STAT5 inhibitors are in phase I or II clinical trials for the treatment of leukemias and graft vs host disease. These studies seem to indicate that such compounds could be well tolerated and useful in reducing the occurrence of resistance to tyrosine kinase inhibitors in chronic myeloid leukemia. Of interest, STAT5 seems to play an important role in the regulation of hematopoietic stem cell self-renewal suggesting that combination therapies including STAT5 inhibitors can erode the cancer stem cell pool and possibly open the way for the complete cancer eradication. In this review, we discuss the implication of STAT5 in hematological malignancies and the results obtained with the novel STAT5 inhibitors.

Signal Transducer and Activator of Transcription 5 (STAT5) protein, a component of the STAT family of signaling proteins, is considered to be an attractive therapeutic target because of its involvement in the progression of acute myeloid leukemia. In an effort to discover potent molecules able to inhibit the phosphorylation-activation of STAT5, twenty-two compounds were synthesized and evaluated on the basis of our knowledge of the activity of 2-(3’,4’,5’-trimethoxybenzoyl)-3-iodoacetamido-6-methoxy benzo[b]furan derivative 1 as a potent STAT5 inhibitor. Most of these molecules, structurally related to compound 1, were characterized by the presence of a common 3’,4’,5’-trimethoxybenzoyl moiety at the 2-position of different benzoheterocycles such as benzo[b]furan, benzo[b]thiophene, indole and N-methylindole. Effects on biological activity of the iodoacetamido group and of different moieties (methyl and methoxy) at the C-3 to C-7 positions were examined. In the series of benzo[b]furan derivatives, moving the iodoacetylamino group from the C-4 to the C-5 or C-6 positions did not significantly affect antiproliferative activity. Compounds 4, 15, 20 and 23 blocked STAT5 signals and induced apoptosis of K562 BCR-ABL positive cells. For compound 23, the trimethoxybenzoyl moiety at the 2-position of the benzo[b]furan core was not essential for potent inhibition of STAT5 activation.

Resistance to imatinib mesylate is an emergent problem in the treatment of Bcr-Abl expressing myelogenous leukemias and additional therapeutic strategies are required. We observed that galangin, a non-toxic, naturally occurring flavonoid was effective as anti-proliferative, and apoptotic agent in Bcr-Abl expressing K562 and KCL22 cells and in imatinib mesylate resistant K562-R and KCL22-R cells. Galangin induced an arrest of cells in G0–G1phase of cell cycle and a decrease in pRb, cdk4, cdk1, cycline B levels; moreover, it was able to induce a monocytic differentiation of leukemic Bcr-Abl+ cells. Of note, galangin caused a decrease in Bcl-2 levels and markedly increased the apoptotic activity of imatinib both in sensitive or imatinib-resistant Bcr-Abl+ cell lines. In contrast, flavonoids unable to modify the Bcl-2 intracellular levels, such as fisetin and chrysin, did not increase the apoptotic effect of imatinib. These data suggest that galangin is an interesting candidate for a combination therapy in the treatment of imatinib-resistant leukemias.

Background Proton pump inhibitors (PPIs) are among the most misused drugs both at the community and hospital level. Recently, possible risks have been underscored, suggesting the importance of limiting PPI use to proven indications. Objective To survey the appropriateness of PPI use in a University hospital in Italy. Setting Azienda Ospedaliera Universitaria Policlinico ‘P. Giaccone’, in Palermo, Italy. Method A one day-observational study, reviewing patients’ medical records to identify treatments with PPIs and the indications for their use. After discharge, a subgroup of the cohort was followed up to assess the continuation of therapy at home. Appropriateness was evaluated according to the indications stated in the official product information sheet and supported by the AIFA notes. Main outcome measure Prevalence and appropriateness of PPI use in the hospital and after discharge. Results In the index day 62.9 % of 343 evaluable patients received a PPI. In only 29.1 % of these, the treatment could be considered appropriate. The most frequent reasons for inappropriate treatment were stress ulcer prophylaxis in low risk patients and unwarranted gastro-protection in drug treated patients. 30.9 % of patients received PPIs for uncertain indications: of these, 25.7 % were “critical” patients admitted in non-ICU wards. Furthermore, as much as 88.2 % of anticancer drug treated patients received PPIs as gastroprotective agents. At discharge 48.6 % of patients received a prescription to continue PPI therapy at home and 75.9 % of the 83 followed up patients were found to be still taking these drugs after on average 3 months from discharge. Conclusion This study confirms a high proportion of inappropriate PPI therapy into the hospital that translates in a prolonged unnecessary administration in the community setting. Further studies are needed to assess the cost-effectiveness of PPI therapy in subgroups of patients at moderate risk for gastric complications to optimize current guidelines.

Pterostilbene and 3,5-hydroxypterostilbene are the natural 3,5-dimethoxy analogs of trans-resveratrol and piceatannol, two compounds which can induce apoptosis in tumor cells. In previous studies we demonstrated the importance of a 3,5-dimethoxy motif in conferring pro-apoptotic activity to stilbene based compounds so we now wanted to evaluate the ability of pterostilbene and 3,5-hydroxypterostilbene in inducing apoptosis in sensitive and resistant leukemia cells. When tested in sensitive cell lines, HL60 and HUT78, 3'-hydroxypterostilbene was 50-97 times more potent than trans-resveratrol in inducing apoptosis, while pterostilbene appeared barely active. However, both compounds, but not trans-resveratrol and piceatannol, were able to induce apoptosis in the two Fas-ligand resistant lymphoma cell lines, HUT78B1 and HUT78B3, and the multi drug-resistant leukemia cell lines HL60-R and K562-ADR (a Bcr-Abl-expressing cell line resistant to imatinib mesylate). Of note, pterostilbene-induced apoptosis was not inhibited by the pancaspase-inhibitor Z-VAD-fmk, suggesting that this compound acts through a caspase-independent pathway. On the contrary, 3'-hydroxypterostilbene seemed to trigger apoptosis through the intrinsic apoptotic pathway: indeed, it caused a marked disruption of the mitochondrial membrane potential delta psi and its apoptotic effects were inhibited by Z-VAD-fmk and the caspase-9-inhibitor Z-LEHD-fmk. Moreover, pterostilbene and 3'-hydroxypterostilbene, when used at concentrations that elicit significant apoptotic effects in tumor cell lines, did not show any cytotoxicity in normal hemopoietic stem cells. In conclusion, our data show that pterostilbene and particularly 3'-hydroxypterostilbene are interesting antitumor natural compounds that may be useful in the treatment of resistant hematological malignancies, including imatinib, non-responsive neoplasms.

Failure to perform the Fas-related apoptosis pathway can account for tumor resistance both to chemotherapeutic agents and to immunological effectors. We studied the role of NK-kappaB in Fas-resistance, employing the Fas-sensitive human T-lymphoma HuT78 cell line and its Fas-resistant variants HuT78B1 and HuT78G9. All these cell lines expressed high levels of constitutively activated NF-kappaB. Pretreatment of cells with NF-kappaB inhibitors (PDTC, MG132, or SN50) strongly enhanced CH11-induced apoptosis in HuT78 and Hut78G9 cells, while only MG132 showed a similar potentiating effect in HuT78B1. The described synergism was significantly inhibited by pretreatment with the anti-Fas-blocking antibody ZB4 or with the pancapsase inhibitor Z-VAD-FMK, but not by capsase-8 or -9 inhibitors. Overall, these data suggest that NF-kappaB inhibition may restore the Fas-pathway in Fas-resistant NF-kappaB-overexpressing tumors.

We synthesized a series of serum-stable covalently linked drugs derived from 3'-C-methyladenosine (3'-Me-Ado) and valproic acid (VPA), which are ribonucleotide reductase (RR) and histone deacetylase (HDAC) inhibitors, respectively. While the combination of free VPA and 3'-Me-Ado resulted in a clear synergistic apoptotic effect, the conjugates had lost their HDAC inhibitory effect as well as the corresponding apoptotic activity. Two of the analogs, 2',5'-bis-O-valproyl-3'-C-methyladenosine (A160) and 5'-O-valproyl-3'-C-methyladenosine (A167), showed promising cytotoxic activities against human hematological and solid cancer cell lines. A167 was less potent than A160 but had interesting features as an RR inhibitor. It inhibited RR activity by competing with ATP as an allosteric effector and concomitantly reduced the intracellular deoxyribonucleoside triphosphate (dNTP) pools. A167 represents a novel lead compound, which in contrast to previously used RR nucleoside analogs does not require intracellular kinases for its activity and therefore holds promise against drug resistant tumors with downregulated nucleoside kinases.

STATs are transcription factors acting as intracellular signaling after stimulation with cytokines, growth factors and hormones. STAT5 is also constitutively active in many forms of cancers, including chronic myelogenous leukemia, acute lymphoblastic leukemia and Hodgkin's lymphoma. Recently, literature reported that the neuroleptic drug pimozide inhibits STAT5 phosphorylation inducing apoptosis in CML cells. We undertook an investigation from pimozide structure, obtaining simple derivatives with cytotoxic and STAT5-inhibitory activity, two of them markedly more potent than pimozide.

Considering that the stereochemistry of the C9-C10 alkenyl portion of natural 9-cis-RA, as the one of the olefinic moiety of the previously described isoxazole retinoid 4, seems of particular importance for their apoptotic activity, we prepared a novel class of TTNPB analogues bearing both the cis or trans configuration of the alkenyl portion. The compounds were evaluated in vitro for their cytotoxic and apoptotic activities. We discovered that the cis-TTNPB 9c possesses apoptotic activity comparable with that of the retinoid 4. Moreover, the amino arotinoid 16c showed potent apoptotic activity in HL60 promyelocytic leukemia cells. Interestingly, 16c proved to be a particularly potent apoptosis-inducing agent active in multidrug resistant (MDR) cell lines. Therefore, to the best of our knowledge, 16c may represent the first known aminoarotinoid endowed with potent apoptotic activity in MDR cells. Taken together, these results seem to point out that the cis-stilbene motif of arotinoids may be at least an important feature in conferring cytotoxic and apoptotic activity to this class of compounds.

Hsp90 is considered an interesting therapeutic target for anticancer drug development. Here we describe a new class of 4,5,6,7-tetrahydro-isoxazolo-[4,5-c]-pyridine compounds. A small library of derivatives has been synthesized and investigated. Some reported compounds show interesting properties combining both notable binding to Hsp90 and potent cell growth inhibitory activity. N-5 substitution with a 2,4 resorcinol carboxamide appears crucial for activity. Moreover, a derivative bearing a hydroxamic acid residue bound to C-3 amide portion was found to inhibit both Hsp90 and HDAC6.

The identification of novel compounds modulating the expression/activity of molecular targets downstream to BCR-ABL could be a new approach in the treatment of chronic myeloid leukemias (CMLs) resistant to imatinib or other BCR-ABL-targeted molecules. Recently, we synthesized a new class of substituted 2-(3,4,5-trimethoxybenzoyl)-2-N,N-dimethylamino-benzo[b]furans, and among these 3-iodoacetylamino-6-methoxybenzofuran-2-yl(3,5-trimethoxyphenyl)methanone (TR120) showed marked cytotoxic activity in BCR-ABL-expressing cells. Interestingly, TR120 was more potent than imatinib in cell growth inhibition and apoptosis induction in both BCR-ABL-expressing K562 and KCL22 cells. Moreover, it showed antitumor activity in imatinib-resistant K562-R and KCL22-R cells at concentrations similar to those active in the respective sensitive cells. Further, TR120 induced a marked decrease in signal transducer and activator of transcription 5 (STAT5) expression in K562 cells. Consistent with this effect, it determined a block of cells in the G0-G1 phase of the cell cycle, a decrease in the level of cyclin D1, and a reduction in Bcl-xL expression; however, it did not cause modifications in the Bcl-2 level. Of interest, TR120 had synergistic effects when used in combination with imatinib in both sensitive and resistant cells. Considering that STAT5 is a BCR-ABL molecular target that plays a key role in the pathogenesis of CML as well as in BCR-ABL-mediated resistance to apoptosis, TR120 could potentially be a useful novel agent in the treatment of imatinib-resistant CML.

Introduction Proton pump inhibitors (PPIs) are highly prescribed drugs in Italy and in particular in the Sicilian region but little is known about their use in the hospital setting.Materials and methods PPI utilization and related costs were reviewed retrospectively by examining the pharmaceutical records of drug dispensation to the various wards of the Policlinico Universitario P. Giaccone of Palermo in 2010. Differences in the prescribing rates and drug preferences among the different clinical wards were analyzed.Results A total of 20,420 patients were hospitalized at the Policlinico of Palermo in 2010. Overall, the consumption of PPIs was 120 DDD/100 bed-days for the year 2010 with a total cost of 42,780 euros. Omeprazole and esomeprazole were the most commonly prescribed molecules accounting for over 70% of all prescriptions: nevertheless, wide differences in drug choices were noted even within the same ward. As expected, greater utilization rates were registered in the Internal Medicine and General Surgery departments. In particular, the highest consumption was observed in the Oncology, Geriatry and Obesity Surgery wards, with about 250 DDD/100 bed-days. All wards reported intravenous PPI administration suggesting some inappropriate use.Discussion From our data, PPIs appear to be moderately over-used at the Policlinico of Palermo. This practice may lead to the inappropriate continuation of therapy in primary care, further increasing costs and risks of adverse events. A survey evaluating in more detail the appropriateness of prescriptions is advisable.

Summary Introduction Proton pump inhibitors (PPIs) are highly prescribed drugs in Italy and in particular in the Sicilian region but little is known about their use in the hospital setting. Materials and methods PPI utilization and related costs were reviewed retrospectively by examining the pharmaceutical records of drug dispensation to the various wards of the Policlinico Universitario P. Giaccone of Palermo in 2010. Differences in the prescribing rates and drug preferences among the different clinical wards were analyzed. Results A total of 20,420 patients were hospitalized at the Policlinico of Palermo in 2010. Overall, the consumption of PPIs was 120 DDD/100 bed-days for the year 2010 with a total cost of 42,780 euros. Omeprazole and esomeprazole were the most commonly prescribed molecules accounting for over 70% of all prescriptions: nevertheless, wide differences in drug choices were noted even within the same ward. As expected, greater utilization rates were registered in the Internal Medicine and General Surgery departments. In particular, the highest consumption was observed in the Oncology, Geriatry and Obesity Surgery wards, with about 250 DDD/100 bed-days. All wards reported intravenous PPI administration suggesting some inappropriate use. Discussion From our data, PPIs appear to be moderately over-used at the Policlinico of Palermo. This practice may lead to the inappropriate continuation of therapy in primary care, further increasing costs and risks of adverse events. A survey evaluating in more detail the appropriateness of prescriptions is advisable.

Treatment of advanced head and neck cancer is still a matter of controversy. Although current chemotherapy regimens are able to induce high response rates, they have not shown improved survival. We employed a combination of cisplatin (CDDP), 5-fluorouracil (5FU) and 1-folinic acid (1-FA) in a 6-hour infusion schedule easy to administer on an outpatient basis. 49 patients have been included to date. The treatment plan consists of 5-FU (375 mg/m(2)) plus 1-FA (100 mg/m(2)) in a 4-hour i.v. infusion followed by a 2-hour i.v. administration of CDDP (20 mg/m(2)). This therapy was repeated for five consecutive days and recycled every 3-4 weeks. Out of 46 evaluable patients there were 6 complete responses (CR) and 23 partial responses (PR) for an overall response rate of 63%. Overall survival was 10.2 months (mean). Untreated patients had a higher probability of response as well as patients with naso-oropharyngeal primary tumor. Toxicity was generally mild with leukopenia, anemia and vomiting being the most frequent side effects. In conclusion, this combination appears well tolerated and active in the palliation of advanced head and neck cancer. However we think that increasing dose intensity of standard regimens and experimental new therapeutic approaches are needed to improve the clinical outcome of this disease.

We enrolled 118 chemonaive cancer patients (pts) to receive OND i.v. dl or GRA i.v. dl. Seventy of the 118 pts received moderately emetogenic (ME) chemotherapy (140 cycles), while 48 received highly emetogenic (HE) chemotherapy (93 cycles). Therapeutic success was obtained in 89% (OND) vs 94% (GRA) cycles of HE and in 96.8% (OND) vs 95.6% (GRA) cycles of ME. The main toxicities were headache (24%, OND; 23%, GRA); light-headedness (13%, OND; 18%, GRA); constipation (11%, OND; 6%, GRA). In conclusion, we think that OND and GRA are effective and the two drugs are equally active and toxic.

We enrolled 11 consecutive pre-treated resistant advanced cancer patients to receive hydroxyurea (HU) (as modulator of MDR) 10 mg/kg/day (d) p.o. d 1-14 in association with DXR (d 15) alone or in combination with VDS (d 15) or VP16 (d 15-17) in presence, respectively, of soft tissue sarcoma, breast carcinoma, lung and gastric carcinoma. We obtained a stabilization of disease (NC) in 62.5% of patients, with a mean duration of 6 months. The mean survival was 12.2+ months for NC and 6 months for progressive disease (PD). No severe or unexpected adverse events were reported over 34 cycles administered; the most frequently recorded side effects were haematological and gastrointestinal toxicity. It seems that at the dosage we used, HU is poorly active in overcoming MDR; further studies with larger number of patients and different dosage are needed.

Histone deacetylase (HDAC) inhibitors are a new class of epigenetic agents that were reported to enhance the cytotoxic effects of classical anticancer drugs through multiple mechanisms. However, which of the possible drug combinations would be the most effective and clinically useful are to be determined. We treated the HL60 and NB4 promyelocytic leukaemia cells with a combination of the ribonucleotide reductase (RR) inhibitor 3'-C-methyladenosine (3'-Me-Ado) and several hydroxamic acid-derived HDAC inhibitors, including two recently synthesized molecules, MC1864 and MC1879, and the reference compound trichostatin A (TSA). The results showed significant growth inhibitory and apoptotic synergistic effects with the combinations. Hence, we evaluated the effects of the combinations on cell cycle distribution and on the level of several proteins involved in the apoptotic process (p21, caspase-3, Bcl-2, Bax, AIF). Since HDAC inhibitors increased the G1-S transition block induced by 3'-Me-Ado, an effect on RR activity was hypothesized. Indeed, the HPLC evaluation of intracellular deoxyribonucleotide (dNTP) pools showed that both TSA and MC1864 induced a decrease in dNTPs, even if with a somewhat different pattern, suggesting that RR inhibition contributes to the observed synergism. Furthermore, while TSA was shown to activate the intrinsic apoptotic pathway, MC1864 induced a dose-dependent increase in ROS and AIF levels. Moreover, the treatment with the radical scavenger N-acetylcysteine determined a significant inhibition of MC1864- but not TSA-mediated synergistic effects. Hence, our findings are consistent with a possible role of HDAC inhibitor mediated-ROS induction in RR inhibition and in the potentiation of RR inhibitor-mediated apoptosis.

Twenty consecutive patients with advanced breast cancer were treated with a combination of cyclophosphamide 600 mg/m2 i.v. on day 1, epidoxorubicin 75 mg/m2 on day 1, and 5-fluorouracil 375 mg/m2 i.v. with folinic acid 200 mg/m2 i.v. on days 1----3. The overall response rate was 60%, with 10% of patients showing a complete response with a mean duration of 11.1 + months, and 50% of patients a partial response of 7.4 + months. A stabilization of 5.2 + months was obtained in 20% of cases, while 20% of patients progressed. The most frequently observed toxicity was leukopenia, while expected mucosal toxicities were rather mild.

A series of easily affordable phenothiazine derivatives bearing a rigid but-2-ynyl amino side chain were synthesized and tested to evaluate the MDR reverting activity and full antitumor profile. Some compounds endowed with remarkable MDR reverting effect were identified, and the most active one ( 6c ) was shown to increase doxorubicin retention in multidrug resistant cells, suggesting a direct interaction with P-glycoprotein. Furthermore, a broad range of cellular activities were observed for different compounds. In particular, the ability of some derivatives to induce antiproliferative effects on resistant cell lines and to interfere with the G 1 phase of the cell cycle, a phase usually not affected by classical antitumor agents, was noted. Moreover, the most cytotoxic compounds of the series were able to induce apoptosis in resistant cell lines, via an atypical pathway of caspase cascade activation, and a synergistic effect in combination with doxorubicin was also found.

New effective cytotoxic agents and combinations are urgently needed in cancer treatment. The enzyme inosine monophosphate dehydrogenase is a potentially useful target for drug development, since its activity has been shown to be amplified in malignant cells. Thiophenfurin, an inhibitor of the enzyme synthesized by us, is endowed with a significant apoptotic activity in promyelocytic leukaemia HL60 cells. Since retinoids were successfully employed in the treatment of patients with leukaemia, demonstrating significant differentiation-inducing and apoptotic effects, we carried out this study to evaluate the effects of the combination of thiophenfurin and several retinoid molecules, acting in different phases of the cell cycle in vitro. The results show that thiophenfurin is capable of eliciting significant S phase-specific antiproliferative effects in different sensitive and resistant cell lines with the IC50s ranging from 6.7 to 26 microM. When HL60 cells were treated with thiophenfurin in combination with retinoids, the effects on cell growth were additive or synergistic, depending on the kind of retinoid used and the sequence of treatment. In particular, we observed additive effects when the cells were exposed to thiophenfurin and all-transretinoic acid either simultaneously or sequentially. Instead, when the new heterocyclic retinoid isoxazole benzoic acid was used, synergism was obtained in the cells treated sequentially. The combination of thiophenfurin and isoxazole benzoic acid determined synergistic apoptotic effects through a mitochondrion-dependent mechanism, suggesting the possible usefulness of this combination in the treatment of leukaemia.

IAPs (inhibitors of apoptosis proteins) might have a major role in the apoptotic resistance that marks many cancers. The studies on IAPs in human HCC have focused on survivin or XIAP, indicating that their new or increased expression in this tumor is associated with a more unfavorable prognosis. The present results corroborate these findings, emphasizing the role that the coordinated expression of different IAPs and alternative splice variants might play in the adverse biology of hepatocellular carcinoma.

Two new series of combretastatin (CA-4) analogues have been prepared. The alkenyl motif of CA-4 was replaced either by a five-membered heterocyclic (isoxazoline or isoxazole) or by a six-membered ring (pyridine or benzene). The new compounds have been evaluated for their effects on tubulin assembly and for cytotoxic and apoptotic activities. Five compounds (18b, 20a, 21a, 34b, and 35b) demonstrated an attractive profile of cytotoxicity (IC501 microM) and apoptosis-inducing activity but poor antitubulin activity. The isoxazoline derivatives 18b, 20a, and 21a, demonstrated potent apoptotic activity different from that of natural CA-4. Their ability to block most cells in the G2 phase suggests that these compounds could act on targets different from the mitotic spindle. This would indicate activation of both the intrinsic and the extrinsic apoptotic pathways. The data suggest unambiguously that structural alteration of the stilbene motif of CA-4 can be extremely effective in producing potent apoptosis-inducing agents.

Background: The effects of the A3 adenosine receptor (A3AR) agonist IB-MECA were examined in HL-60 leukemia and in its multidrug-resistant variant HL-60R cells. Methods: Cytotoxicity was evaluated by MTS assays and apoptosis by flow cytometry analyses of DNA fragmentation and phosphatidylserine exposure. The mRNAs of A3AR and inhibitor of apoptosis proteins (IAPs) were determined by RT-PCR. Results: A3AR expression was similar in HL-60 and HL-60R cells. At ≧100 µM, IB-MECA exhibited strong cytotoxic and apoptotic effects in HL-60, but not in HL-60R cells. This activity was not modified by the A3AR antagonist VUF5574, the P-glycoprotein inhibitor verapamil, the adenosine uptake inhibitor NBTI or the anti-Fas antibody ZB4. HL-60R cells showed higher levels of different IAPs than HL-60 cells. IB-MECA 100 µM downregulated HIAP1, NAIP and survivin mRNAs in HL-60, but not in HL-60R cells. Conclusions: The antitumor effects of IB-MECA are not mediated by A3AR in HL-60 cells, where the proapoptotic mechanism of the compound may involve downregulation of IAPs. The resistance of HL-60R cells to IB-MECA may depend on their elevated levels of IAPs.

We have investigated the expression of the IAPs (inhibitory of apoptosis proteins) in the human HL-60 leukemia and in its multidrug resistant, P-glycoprotein (P-gp) over-expressing variant, HL-60R. HL-60R exhibits resistance to apoptosis induced from P-gp substrate drugs and also from other triggers (cisplatin, TNF-alpha, Fas ligation, TRAIL, IFN-gamma and serum starvation) not related to the multidrug transporter. Except for c-IAP-1 mRNA, HL-60R significantly over-expressed both the mRNAs and the proteins of all the IAPs studied, i.e. c-IAP-1, c-IAP-2, XIAP, NAIP and survivin. Determination of the DNA-binding capacity of NF-kappaB (p50 or p65 subunits) indicated that, while HL-60 cells show constitutive activation of p50 only, HL-60R cells contain the activated forms of both p50 and p65. Since p65 is necessary to form the NF-kappaB heterodimers able to increase transcription, its presence in HL-60R cells might well correlate to their increased levels of IAPs and, possibly of P-gp, which, reportedly, are NF-kappaB target genes. These results underline the possible role that the coordinated over-expression of the different IAPs may play in tumor cell resistance to drug induced apoptosis. Inhibition of NF-kappaB might be a useful strategy to block their up-regulation.

In a search for retinoic acid (RA) receptor ligands endowed with potent apoptotic activity, a series of novel arotinoids were prepared. Because the stereochemistry of the C9-alkenyl portion of natural 9-cis-RA and the olefinic moiety of the previously synthesized isoxazole retinoid 4 seems to have particular importance for their apoptotic activity, novel retinoid analogues with a restricted or, vice versa, a larger flexibility in this region were designed and prepared. The new compounds were evaluated in vitro for their ability to activate natural retinoid receptors and for their differentiation-inducing activity. Cytotoxic and apoptotic activities were, in addition, evaluated. In general, these analogues showed low cytotoxicity, with the restricted structures being slightly more active than the more flexible ones. As an exception, however, the isoxazole retinoid 15b proved to be particularly able to induce apoptosis at concentrations5 microM, showing a higher activity than the classical retinoids such as all-trans-RA, 13-cis-RA, and 9-cis-RA and the previously described synthetic retinoid 4. 15b also exhibited a good affinity for the retinoid receptors. Interestingly, another important property of 15b was its ability to induce apoptosis in the HL60R multidrug-resistant (MDR) cell line, at the same concentration as is effective in HL60. Therefore, 15b represents a new retinoid possessing high apoptotic activity in an MDR cell line. The ability of 15b to act on K562 and HL60R cells suggests that this compound may have important implications in the treatment of different leukemias, and its structure could offer an interesting model for the design of new compounds endowed with apoptotic activity on MDR- and retinoid-resistant malignancies.

Many anticancer drugs are able to induce apoptosis in tumor cells but the mechanisms underlying this phenomenon are poorly understood. Some authors reported that the p53 tumor suppressor gene may be responsible for drug-induced apoptosis; however, chemotherapy-induced apoptosis can also be observed in p53 negative cells. Recently, doxorubicin (DXR) was reported to induce CD95L expression to mediate apoptosis through the CD95/CD95L system. Thus, an impairment of such a system may be involved in drug resistance. We evaluated the in vitro antitumor activity of several cytotoxic drugs on two human p53-negative T-cell lymphoma cell lines, the HUT78-B1 CD95L-resistant cell line and the HUT78 parental CD95L-sensitive cell line. We demostrated by Western blotting assay that DXR and etoposide (VP-16) were able to induce CD95L expression after 4 h of treatment. In contrast, they were unable to induce the expression of p53. DXR, at concentrations ranging from 0.001 - 1 microg/ml, and VP16, at concentrations ranging from 0.05 - 1 microg/ml, were equally cytotoxic and induced apoptosis in both cell lines as assessed by fluorescence microscopy and flow cytometry analyses. Although we observed a slightly reduced percentage of apoptotic cells in HUT78B1 when compared with the parental HUT78 cells after few hours of drug exposure, this difference was no longer evident at 48 or 72 h. Similarly, the exposure of HUT78 cells to a CD95-blocking antibody partially reduced early apoptosis (24 h) without affecting the long-term effects of the drugs including cytotoxicity. Furthermore, as observed with DXR and VP-16, both the CD95L-sensitive and the CD95L-resistant cell lines resulted equally sensitive to the cytotoxic effects of a number of different cytotoxic drugs (vincristine, camptothecin, 5-fluorouracil and methotrexate). The treatment with the Caspase-3 tetrapeptide aldehyde inhibitor, Ac-DEVD-CHO, did not affect the DXR-induced apoptosis whereas it only modestly inhibited apoptosis and cytotoxicity of VP-16, while Z-VAD.FMK, a Caspase inhibitor that prevents the processing of Caspase-3 to its active form, was able to block DXR-induced apoptosis at 24 h but not at 48 h. Thus, our results do not confirm a crucial role for the CD95/CD95L system in drug-induced apoptosis and suggest the involvement of alternative p53-independent pathways at least in this experimental model system.

The role of chemotherapy in refractory metastatic breast cancer is still debated. We employed a schedule of cisplatin, mitomycin and vindesine in twenty-one anthracycline- or anthraquinone-pretreated breast cancer patients. The most relevant characteristics of our group were a good performance status (mean Karnofsky index 84) and a high percentage of bone disease (71%). Out of 20 evaluable patients, 4 (20%) achieved a partial response with a median duration of 3.7 months. Median survival was 12.5 months. Severe gastrointestinal toxicity was reported in 66% of patients and G3 alopecia was seen in 24%. Other side effects, including hematological, were negligible. On the basis of the low response rate and poor tolerability we do not reccommend this combination as salvage treatment in metastatic breast cancer. The use of cisplatin-based regimens in untreated patients waits further investigation.