Targeting HDAC2-Mediated Immune Regulation to Overcome Therapeutic Resistance in Mutant Colorectal Cancer.

A large body of clinical and experimental evidence indicates that colorectal cancer is one of the most common multifactorial diseases. Although some useful prognostic biomarkers for clinical therapy have already been identified, it is still difficult to characterize a therapeutic signature that is able to define the most appropriate treatment. Gene expression levels of the epigenetic regulator histone deacetylase 2 (HDAC2) are deregulated in colorectal cancer, and this deregulation is tightly associated with immune dysfunction. By interrogating bioinformatic databases, we identified patients who presented simultaneous alterations in HDAC2, class II major histocompatibility complex transactivator (CIITA), and beta-2 microglobulin (B2M) genes based on mutation levels, structural variants, and RNA expression levels. We found that B2M plays an important role in these alterations and that mutations in this gene are potentially oncogenic. The dysregulated mRNA expression levels of HDAC2 were reported in about 5% of the profiled patients, while other specific alterations were described for CIITA. By analyzing immune infiltrates, we then identified correlations among these three genes in colorectal cancer patients and differential infiltration levels of genetic variants, suggesting that HDAC2 may have an indirect immune-related role in specific subgroups of immune infiltrates. Using this approach to carry out extensive immunological signature studies could provide further clinical information that is relevant to more resistant forms of colorectal cancer.

Feijoa sellowiana derived natural Flavone exerts anti-cancer action displaying HDAC inhibitory activities.

Curative properties of some medicinal plants such as the Feijoa sellowiana Bert. (Myrtaceae), have been often claimed, although the corresponding molecular mechanism(s) remain elusive. We report here that the Feijoa acetonic extract exerts anti-cancer activities on solid and hematological cancer cells. Feijoa extract did not show toxic effects on normal myeloid progenitors thus displaying a tumor-selective activity. In the Feijoa acetonic extract, fractionation and subsequent purification and analyses identified Flavone as the active component. Flavone induces apoptosis which is accompanied by caspase activation and p16, p21 and TRAIL over-expression in human myeloid leukemia cells. Use of ex vivo myeloid leukemia patients blasts confirms that both the full acetonic Feijoa extract and its derived Flavone are able to induce apoptosis. In both cell lines and myeloid leukemia patients blasts the apoptotic activity of Feijoa extract and Flavone is accompanied by increase of histone and non-histone acetylation levels and by HDAC inhibition. Our findings show for the first time that the Feijoa apoptotic active principle is the Flavone and that this activity correlates with the induction of HDAC inhibition, supporting the hypothesis of its epigenetic pro-apoptotic regulation in cancer systems.

Feasibility of autologous peripheral blood stem cell transplantation in elderly patients with acute myeloid leukemia.

Most studies showing that autologous stem cell transplantation (ASCT) is feasible in older patients with acute myeloid leukemia (AML) referred to highly selected patients considered as eligible after complete remission (CR) achievement and bone marrow or peripheral blood stem cell (PBSC) collection. This study evaluated the feasibility of ASCT from 155 consecutive AML patients aged over 60 years (median age 72 years, range 61 - 94) programmed to receive ASCT by using PBSCs after CR achievement. Overall, 90 out of 155 patients (58%) were judged as eligible for aggressive chemotherapy and 45 (50%) achieved CR. Among these, 36 (80%) received consolidation and 32 (89% of consolidated) were monitored for PBSC mobilization. A successful collection was registered in 25/32 patients (78% of monitored). Finally, 20 patients received ASCT. Reasons for not autografting five mobilizing patients included relapse pre-ASCT, toxicity, and refusal. Median survival was 4 months for the whole patient population and 19 months for patients actually autografted. Overall, 20 out of 90 patients accrued into intensive chemotherapy (22%) and 20 out of the entire patient population (13%) underwent ASCT. It is concluded that APBSCT can result in an improvement of therapeutic results in AML of the elderly, but it is feasible in a minority of selected patients.

Rexinoid-triggered differentiation and tumor-selective apoptosis of acute myeloid leukemia by protein kinase A-mediated desubordination of retinoid X receptor.

Apart from PML-retinoic acid receptor-alpha (RARalpha) acute promyelocytic leukemia all other acute myeloid leukemias (AML) are unresponsive to retinoid differentiation therapy. However, elevating the levels of cyclic AMP (cAMP) confers onto retinoid X receptor (RXR)-selective agonists ("rexinoids") the ability to induce terminal granulocyte differentiation and apoptosis of all-trans retinoic acid-resistant and insensitive AML cells and patients' blasts. Protein kinase A activation leads to corepressor release from the RAR subunit of the RAR-RXR heterodimer, resulting in "desubordination" of otherwise silent RXR, which acquires transcriptional competence in response to cognate ligands. Rexinoid-cAMP induction of endogenous RARbeta is blunted in mouse embryo fibroblasts lacking RARs, but reintroduction of exogenous RARalpha reestablishes responsiveness, thus confirming that the RARalpha-RXR heterodimer is the rexinoid mediator. The apoptogenic effect of this treatment involves enhanced expression of the death receptor DR5 and its cognate ligand, tumor necrosis factor-related apoptosis inducing ligand, both of which are known to induce apoptosis in a tumor cell-selective manner and lead to the activation of initiator caspases. Immunohistochemistry confirmed induction of tumor necrosis factor-related apoptosis inducing ligand and DR5 in AML patient blasts cultured ex vivo. AML patients' blasts responded to rexinoid-cAMP combination treatment with induction of maturation and apoptosis, independent of karyotype, immunophenotype, and French-American-British classification status. Clonogenic assays revealed complete inhibition of blast clonogenicity in four out of five tested samples. Our results suggest that despite the genetic, morphologic, and clinical variability of this disease, the combination of rexinoids and cAMP-elevating drugs, such as phosphodiesterase inhibitors, might lead to a novel therapeutic option for AML patients by inducing a tumor-selective death pathway.

Fludarabine and cytarabine as continuous sequential infusion for elderly patients with acute myeloid leukemia.

BACKGROUND AND OBJECTIVES: A phase II study was conducted to investigate the effects of a therapeutic program based on the combination of fludarabine and cytarabine (ARA-C) administered as a sequential continuous infusion in untreated elderly patients with acute myeloid leukemia (AML). DESIGN AND METHODS: Sixty-three patients with non-M3 AML, median age 69 years (range 61-81), were accrued. Twenty-four patients (38%) had AML secondary to myelodysplastic syndrome. Fludarabine and ARA-C were administered as a continuous sequential infusion for 72 and 96 hours, respectively, after a loading dose. Patients achieving complete remission (CR) were intended to receive an additional course, followed by autologous stem cell transplantation (ASCT). RESULTS: Overall, 42 patients (67%) achieved CR. There were 10 induction deaths (16%), while 11 patients were refractory (17%). Among those achieving a remission, 35 patients (83%) received the planned consolidation course and 29 underwent mobilization of CD34+ cells into the peripheral blood for collection, which was successful in 23 (79%). Overall, 17 patients (27% of the whole population) received ASCT. The median overall and disease-free survival were both 10 months. INTERPRETATION AND CONCLUSIONS: Patients with an intermediate karyotype and those receiving ASCT had a significantly better clinical outcome. Results in terms of CR achievement, CD34+ cell collection and ASCT feasibility. A longer follow up is needed in order to evaluate the actual benefit on long-term survival.

High-dose idarubicin and busulphan as conditioning to autologous stem cell transplantation in adult patients with acute myeloid leukaemia.

Between 30 and 50% of patients with acute myeloid leukaemia (AML) relapse after autologous stem cell transplantation (ASCT). One possibility of reducing the relapse rate could be the adoption of conditioning regimens specifically designed for AML. We report treatment results achieved with a new conditioning for ASCT, based on high-dose idarubicin (IDA) plus oral busulphan. Patients (n = 40) were conditioned with a regimen consisting of 3 d continuous intravenous infusion IDA at 20 mg/m2, followed by 4 d conventional dose oral busulphan. Unpurged peripheral blood stem cells were used in all cases. All patients had non-M3-AML and were in first complete remission (CR). The median number of CD34+ cells infused was 6.9 x 10(6)/l (2.6-24). No case of transplant-related mortality occurred. In all cases, left ventricular ejection fraction remained unmodified after ASCT. Thirty-three of 40 patients (82%) had grade 3-4 mucositis requiring total parenteral nutrition in all cases. After a median follow up for surviving patients of 32 months from ASCT, 30 patients (75%) are alive and 26 (65%) are in continuous CR. Our data show that a conditioning regimen based on high-dose IDA plus busulphan results in an encouraging reduction of the relapse rate after ASCT in AML.

Ifosfamide, epirubicin and etoposide (IEV) regimen as salvage and mobilization therapy for refractory or early relapsing patients with aggressive non-Hodgkin's lymphoma.

The prognosis of early relapsing or refractory aggressive non-Hodgkin's lymphoma (NHL) is still poor. Effective salvage therapy should be able to induce high response rate as well as to mobilize hematopoietic precursors. A combination of ifosfamide, epirubicin and etoposide (IEV) was given to 28 patients with refractory or relapsing high grade NHL (4 lymphoblastic lymphoma and 24 large cell lymphoma). All patients were evaluated for response. After 2 courses of IEV, the overall and complete response rate were 64% and 39%, respectively. All patients were controlled for mobilization of peripheral blood stem cells, which was successful in 26 out of 28 (93%). Overall, 25 out of 26 patients proceeded to autologous stem cell transplantation (ASCT). Toxicity was mild, with no occurrence of severe persisting extra-hematologic side-effects. Following the entire therapeutic program, including IEV and ASCT, median progression free survival has not yet been reached and 21 patients are alive (18 in continuous complete remission) after a median follow-up of 18 months. Our results demonstrate that treatment with IEV regimen is effective in refractory or relapsing aggressive NHL, resulting in a high percentage of successful stem cell mobilization and feasibility of ASCT.

Outpatient-based peripheral blood stem cell transplantation for patients with multiple myeloma.

INTRODUCTION: There is a growing demand for autologous stem cell transplantation (ASCT) in newly diagnosed patients with multiple myeloma (MM), resulting in an increasing pressure on available hospital beds. In addition, more rational utilization of health resources should induce physicians to attempt therapeutic strategies aiming at reduction of costs. The aim of this study was to explore the feasibility and safety of performing ASCT on an outpatient basis, according to an early discharge method. MATERIALS AND METHODS: A total of 28 patients affected by MM and in complete or partial remission were selected to receive ASCT on an outpatient basis. In particular, after conditioning with high-dose melphalan and stem cell infusion, patients were programmed to go home and to be rehospitalized in the case of febrile neutropenia or other severe toxicities. RESULTS: All patients accepted the outpatient-based procedure. Out of 28 patients. 18 (64%) did spend the aplastic phase entirely at home following high-dose chemotherapy and stem cell infusion. A second hospital admission was required in 10 patients (36%). Febrile neutropenia and severe mucositis needing total parenteral nutrition were the most frequent causes of hospitalization. However, there were no documented infections and either fever or mucositis was easily resolved at the time of hematopoietic recovery in all patients. CONCLUSION: ASCT on an outpatient basis is feasible and safe in patients with MM. More than 60% of patients are manageable at home, provided that a caregiver is available.

Fludarabine plus cyclophosphamide for the treatment of advanced chronic lymphocytic leukemia.

OBJECTIVES: Therapeutic results in advanced chronic lymphocytic leukemia (CLL) are still unsatisfactory in terms of complete remission achievement and duration, in spite of the extensive use of purine analogs. The objective of this study was to describe the clinical characteristics and treatment results from a series of 32 patients managed with a therapeutic program based on the combination of fludarabine and cyclophosphamide (CTX). METHODS: Thirty-two patients (median age 63 yr, range 42-75 yr) with newly diagnosed (47%) or refractory-relapsed (53%) CLL were programmed to receive six courses of a 3-d combination of fludarabine at 30 mg/m2/d plus CTX at 300 mg/m2/d. Refractory-relapsed patients had previously received different chemotherapy lines from 1 to 5. RESULTS: Fourteen of 32 (44%) patients achieved a complete remission, 16 (50%) obtained partial remission and two (6%) failed to respond. The CR rate was higher in untreated patients; in particular, CR was achieved in nine of 15 (60%) newly diagnosed cases as opposed to five of 17 (29%) among pretreated patients. Toxicity was caused by myelosuppression and/or infections in most cases. After a median follow-up of 24 months (range 8-48 months), 20 of 32 patients (62%) are alive, and 14 of 32 (44%) are free from progression. Median overall survival and median time to progression were 35 and 25 months, respectively. CONCLUSION: The combination of fludarabine with CTX is effective in advanced CLL with acceptable toxicity, either as first-line therapy or in refractory-relapsed patients. In particular, a considerable rate of complete remission can be achieved in untreated patients. Myelosuppression represents the major side-effect.

High-dose cytarabine as consolidation treatment for patients with acute myeloid leukemia with t(8;21).

Seventeen patients affected by acute myeloid leukemia (AML) with t(8;21) were prospectively programmed to receive three courses of high-dose cytarabine (HDARA-C) as post-remission therapy. The median age was 39 years and in all cases t(8;21) was the only karyotypic abnormality. Complete remission (CR) was achieved in 14 out of 17 cases (82%) and, after first consolidation with NOVIA regimen (intermediate dose ARA-C plus mitoxantrone), all patients received the three planned courses of HDARA-C (3g/m(2) q12h on days 1, 3, 5). There were two documented infections, while all patients experienced fever of unknown origin (FUO). Nonhematological toxicity was mild. Thirteen out of 14 patients are in continuous CR after a median follow-up of 44 months. One patient relapsed at 16 months and, following CR2 achievement, underwent allogeneic transplantation; he died 3 months later while in CR from acute graft versus host disease (GVHD). Survival at 5 years is projected at 79%. Our data confirm the efficacy of repeated courses of HDARAC for patients with t(8;21) AML.