Breast cancer screening adhesion among migrants: a matter of communication strategy?

Background

Migrants’ engagement to cancer screening programs is a relevant issue for universalistic health systems. To increase breast cancer screening coverage among migrant women, a public-private partnership involving a multidisciplinary team of Primary Care, Public Health, Hospital and private social workers has been built up in a district in Italy. The team worked in two steps, planning health promotion (HP) meetings addressing women in refugees’ reception programs and a web-based workshop involving intercultural mediators (IMs) and community health promoters.

Objectives

The workshop, involving 10 professionals among IMs and community health promoters, realized in 3 online meetings during March ‘22, aimed at identifying communication tools to enable migrants’ participation to breast cancer screening and increasing health literacy (HL) and cultural competence (CC) among the team. A participatory approach, supported by learning methods, such as storytelling and role-play, has been adopted to identify the major barriers to access to screening and public health messages. Participants worked on critical words and concepts, highlighted during HP meetings, accounting for HL, literacy, language skills, communication techniques and different perspectives about health and prevention.

Results

Several barriers, such as lack of knowledge on preventive initiatives and different approaches to health, decrease the perception of cancer risk. Others, like family and work duties, influence the adhesion. Fear or shame about the exam and linguistic issues are further hampering factors. Participants pointed out text, audio and video messages, in Italian and native plain language, as useful tools to explain the screening procedure and give relevant and practical information supported by simple and clear illustrations to diffuse via WhatsApp.

Conclusions

The intervention enabled the team to improve HL and CC defining suitable communication strategies for cancer screening programs.

Key messages

Dynamical Generation of Elementary Fermion Mass: First Lattice Evidence

Using lattice simulations we demonstrate from first principles the existence of a nonperturbative mechanism for elementary particle mass generation in models with gauge fields, fermions, and scalars, if an exact invariance forbids power divergent fermion masses and fermionic chiral symmetries broken at UV scale are maximally restored. We show that in the Nambu-Goldstone phase a fermion mass term, unrelated to the Yukawa operator, is dynamically generated. In models with electroweak interactions weak boson masses are also generated, opening new scenarios for beyond the standard model physics.

Ectopic expression of PLC-β2 in non-invasive breast tumor cells plays a protective role against malignant progression and is correlated with the deregulation of miR-146a

Cells in non‐invasive breast lesions are widely believed to possess molecular alterations that render them either susceptible or refractory to the acquisition of invasive capability. One such alteration could be the ectopic expression of the β2 isoform of phosphoinositide‐dependent phospholipase C (PLC‐β2), known to counteract the effects of hypoxia in low‐invasive breast tumor‐derived cells. Here, we studied the correlation between PLC‐β2 levels and the propensity of non‐invasive breast tumor cells to acquire malignant features. Using archival FFPE samples and DCIS‐derived cells, we demonstrate that PLC‐β2 is up‐regulated in DCIS and that its forced down‐modulation induces an epithelial‐to‐mesenchymal shift, expression of the cancer stem cell marker CD133, and the acquisition of invasive properties. The ectopic expression of PLC‐β2 in non‐transformed and DCIS‐derived cells is, to some extent, dependent on the de‐regulation of miR‐146a, a tumor suppressor miRNA in invasive breast cancer. Interestingly, an inverse relationship between the two molecules, indicative of a role of miR‐146a in targeting PLC‐β2, was not detected in primary DCIS from patients who developed a second invasive breast neoplasia. This suggests that alterations of the PLC‐β2/miR‐146a relationship in DCIS may constitute a molecular risk factor for the appearance of new breast lesions. Since neither traditional classification systems nor molecular characterizations are able to predict the malignant potential of DCIS, as is possible for invasive ductal carcinoma (IDC), we propose that the assessment of the PLC‐β2/miR‐146a levels at diagnosis could be beneficial for identifying whether DCIS patients may have either a low or high propensity for invasive recurrence.

Protective role of all-trans retinoic acid (ATRA) against hypoxia-induced malignant potential of non-invasive breast tumor derived cells

Background

The presence of hypoxic areas is common in all breast lesions but no data clearly correlate low oxygenation with the acquisition of malignant features by non-invasive cells, particularly by cells from ductal carcinoma in situ (DCIS), the most frequently diagnosed tumor in women.

Methods

By using a DCIS-derived cell line, we evaluated the effects of low oxygen availability on malignant features of non-invasive breast tumor cells and the possible role of all-trans retinoic acid (ATRA), a well-known anti-leukemic drug, in counteracting the effects of hypoxia. The involvement of the β2 isoform of PI-PLC (PLC-β2), an ATRA target in myeloid leukemia cells, was also investigated by specific modulation of the protein expression.

Results

We demonstrated that moderate hypoxia is sufficient to induce, in DCIS-derived cells, motility, epithelial-to-mesenchymal transition (EMT) and expression of the stem cell marker CD133, indicative of their increased malignant potential.

Administration of ATRA supports the epithelial-like phenotype of DCIS-derived cells cultured under hypoxia and keeps down the number of CD133 positive cells, abrogating almost completely the effects of poor oxygenation. We also found that the mechanisms triggered by ATRA in non-invasive breast tumor cells cultured under hypoxia is in part mediated by PLC-β2, responsible to counteract the effects of low oxygen availability on CD133 levels.

Conclusions

Overall, we assigned to hypoxia a role in increasing the malignant potential of DCIS-derived cells and we identified in ATRA, currently used in treatment of acute promyelocytic leukemia (APL), an agonist potentially useful in preventing malignant progression of non-invasive breast lesions showing hypoxic areas.

Vav1 downmodulates Akt in different breast cancer subtypes: a new promising chance to improve breast cancer outcome

Targeting different members of the Akt pathways is a promising therapeutic chance in solid tumors including breast cancer. The variable expression levels of Akt isoforms with opposite effects on tumor growth and metastasis, however, make it difficult to select the inhibitors to be used for specific breast tumor subtypes. Using in vitro and in vivo models, we demonstrated here that Vav1, ectopically expressed in invasive breast tumors derived cells, downmodulates Akt acting at expression and/or activation levels depending on tumor subtype. The decreased p‐Akt1 (Ser473) levels are a common effect of Vav1 upmodulation, suggesting that, in breast tumor‐derived cells and independently of their phenotype, Vav1 interferes with signaling pathways ended to specifically recruit Akt1. Only in ER‐negative cell lines, the silencing of Vav1 induced the expression but not the activation of Akt2. A retrospective analysis of early invasive breast tumors allowed to establish the prognostic significance of the p‐Akt/Vav1 relationship. In particular, low Vav1 levels negatively influence the follow‐up of patients with low p‐Akt in their primary tumors and subjected to adjuvant chemotherapy. As the use of specific or pan Akt inhibitors may not be sufficient or may even be detrimental, increasing the levels of Vav1 could be a new approach to improve breast cancer outcomes. This might be particularly relevant for tumors with a triple‐negative phenotype, for which target‐based therapies are not currently available.

Levels of miR-126 and miR-218 are elevated in ductal carcinoma in situ (DCIS) and inhibit malignant potential of DCIS derived cells

A substantial number of ductal carcinoma in situ (DCIS) detected by mammography never progress to invasive ductal carcinoma (IDC) and current approaches fail to identify low-risk patients not at need of adjuvant therapies. We aimed to identify the key miRNAs protecting DCIS from malignant evolution, that may constitute markers for non-invasive lesions. We studied 100 archived DCIS samples, including pure DCIS, DCIS with adjacent IDC and pure DCIS from patients with subsequent IDC in contralateral breast or no recurrence. A DCIS derived cell line was used for molecular and cellular studies. A genome wide study revealed that pure DCIS has higher miR-126 and miR-218 expression than DCIS with adjacent IDC lesions or than IDC. The down-regulation of miR-126 and miR-218 promoted invasiveness in vitro and, in patients with pure DCIS, was associated with later onset of IDC. Survival studies of independent cohorts indicated that both miRNAs play a protective role in IDC. The clinical findings are in agreement with the miRNAs' roles in cell adhesion, differentiation and proliferation. We propose that miR-126 and miR-218 have a protective role in DCIS and represent novel biomarkers for the risk assessment in women with early detection of breast cancer.

Targeting the phosphatidylinositol 3-kinase/Akt/mechanistic target of rapamycin signaling pathway in B-lineage acute lymphoblastic leukemia: An update

Despite considerable progress in treatment protocols, B-lineage acute lymphoblastic leukemia (B-ALL) displays a poor prognosis in about 15-20% of pediatric cases and about 60% of adult patients. In addition, life-long irreversible late effects from chemo- and radiation therapy, including secondary malignancies, are a growing problem for leukemia survivors. Targeted therapy holds promising perspectives for cancer treatment as it may be more effective and have fewer side effects than conventional therapies. The phosphatidylinositol 3-phosphate kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signaling pathway is a key regulatory cascade which controls proliferation, survival and drug-resistance of cancer cells, and it is frequently upregulated in the different subtypes of B-ALL, where it plays important roles in the pathophysiology, maintenance and progression of the disease. Moreover, activation of this signaling cascade portends a poorer prognosis in both pediatric and adult B-ALL patients. Promising preclinical data on PI3K/Akt/mTOR inhibitors have documented their anticancer activity in B-ALL and some of these novel drugs have entered clinical trials as they could lead to a longer event-free survival and reduce therapy-associated toxicity for patients with B-ALL. This review highlights the current status of PI3K/Akt/mTOR inhibitors in B-ALL, with an emphasis on emerging evidence of the superior efficacy of synergistic combinations involving the use of traditional chemotherapeutics or other novel, targeted agents.

Cardiovascular disease-related miRNAs expression: potential role as biomarkers and effects of training exercise

Cardiovascular diseases (CVDs) are one of the most important causes of mortality worldwide, therefore the need of effective preventive strategies is imperative. Aging is associated with significant changes in both cardiovascular structure and function that lower the threshold for clinical signs and symptoms, making older people more susceptible to CVDs morbidity and mortality. microRNAs (miRNAs) modulate gene expression at post-transcriptional level and increasing evidence has shown that miRNAs are involved in cardiovascular physiology and in the pathogenesis of CVDs. Physical activity is recommended by the medical community and the cardiovascular benefits of exercise are multifactorial and include important systemic effects on skeletal muscle, the peripheral vasculature, metabolism, and neuroendocrine systems, as well as beneficial modifications within the myocardium itself. In this review we describe the role of miRNAs and their dysregulation in several types of CVDs. We provide an overview of miRNAs in CVDs and of the effects of physical activity on miRNA regulation involved in both cardiovascular pathologies and age-related cardiovascular changes and diseases. Circulating miRNAs in response to acute and chronic sport exercise appear to be modulated following training exercise, and may furthermore serve as potential biomarkers for CVDs and different age-related CVDs.

Influence of physical exercise on microRNAs in skeletal muscle regeneration, aging and diseases

Skeletal muscle is a dynamic tissue with remarkable plasticity and its growth and regeneration are highly organized, with the activation of specific transcription factors, proliferative pathways and cytokines. The decline of skeletal muscle tissue with age, is one of the most important causes of functional loss of independence in older adults. Maintaining skeletal muscle function throughout the lifespan is a prerequisite for good health and independent living.

Physical activity represents one of the most effective preventive agents for muscle decay in aging.

Several studies have underlined the importance of microRNAs (miRNAs) in the control of myogenesis and of skeletal muscle regeneration and function.

In this review, we reported an overview and recent advances about the role of miRNAs expressed in the skeletal muscle, miRNAs regulation by exercise in skeletal muscle, the consequences of different physical exercise training modalities in the skeletal muscle miRNA profile, their regulation under pathological conditions and the role of miRNAs in age-related muscle wasting.

Specific miRNAs appear to be involved in response to different types of exercise and therefore to play an important role in muscle fiber identity and myofiber gene expression in adults and elder population.

Understanding the roles and regulation of skeletal muscle miRNAs during muscle regeneration may result in new therapeutic approaches in aging or diseases with impaired muscle function or re-growth.

Vav1 is necessary for PU.1 mediated upmodulation of miR-29b in acute myeloid leukaemia-derived cells

It has been recently demonstrated that high pre‐treatment levels of miR‐29b positively correlated with the response of patients with acute myeloid leukaemia (AML) to hypomethylating agents. Upmodulation of miR‐29b by restoring its transcriptional machinery appears indeed a tool to improve therapeutic response in AML. In cells from acute promyelocytic leukaemia (APL), miR‐29b is regulated by PU.1, in turn upmodulated by agonists currently used to treat APL. We explored here the ability of PU.1 to also regulate miR‐29b in non‐APL cells, in order to identify agonists that, upmodulating PU.1 may be beneficial in hypomethylating agents‐based therapies. We found that PU.1 may regulate miR‐29b in the non‐APL Kasumi‐1 cells, showing the t(8;21) chromosomal rearrangement, which is prevalent in AML and correlated with a relatively low survival. We demonstrated that the PU.1‐mediated contribution of the 2 miR‐29b precursors is cell‐related and almost completely dependent on adequate levels of Vav1. Nuclear PU.1/Vav1 association accompanies the transcription of miR‐29b but, at variance with the APL‐derived NB4 cells, in which the protein is required for the association of PU.1 with both miRNA promoters, Vav1 is part of molecular complexes to the PU.1 consensus site in Kasumi‐1. Our results add new information on the transcriptional machinery that regulates miR‐29b expression in AML‐derived cells and may help in identifying drugs useful in upmodulation of this miRNA in pre‐treatment of patients with non‐APL leukaemia who can take advantage from hypomethylating agent‐based therapies.

Impact of physical exercise in cancer survivors during and after antineoplastic treatments

Cancer patients experience symptoms and adverse effects of treatments that may last even after the end of treatments. Exercise is a safe, non-pharmacological and cost-effective therapy that can provide several health benefits in cancer patient and survivors, reducing cancer symptoms and cancer treatment side effects. The purpose of this review is to describe how the physical exercise is capable to reduce cancer symptoms and cancer treatment side effects. We realized a pragmatic classification of symptoms, dividing them into physical, psychological and psycho-physical aspects. For each symptom we discuss causes, therapies, we analyse the effects of physical exercise and we summarize the most effective type of exercise to reduce the symptoms. This review also points out what are the difficulties that patients and survivors face during the practice of physical activity and provides some solutions to overcome these barriers. Related to each specific cancer, it emerges that type, frequency and intensity of physical exercise could be prescribed and supervised as a therapeutic program, like it occurs for the type, dose and duration of a drug treatment.

Healthy CD4+ T lymphocytes are not affected by targeted therapies against the PI3K/Akt/mTOR pathway in T-cell acute lymphoblastic leukemia

An attractive molecular target for novel anti-cancer therapies is the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway which is commonly deregulated in many types of cancer. Nevertheless, the effects of PI3K/Akt/mTOR inhibitors on T lymphocytes, a key component of immune responses, have been seldom explored. In this study we investigated the effects on human CD4+ T-cells of a panel of PI3K/Akt/mTOR inhibitors: BGT226, Torin-2, MK-2206, and ZSTK474. We also assessed their efficacy against two acute leukemia T cell lines. T lymphocytes were stimulated with phytohemagglutinin. Inhibitor effects on cell cycle and apoptosis were analyzed by flow cytometry, while cytotoxicity was assessed by MTT assays. In addition, the activation status of the pathway as well as induction of autophagy were analyzed by Western blotting. Quiescent healthy T lymphocytes were unaffected by the drugs whereas mitogen-stimulated lymphocytes as well as leukemic cell lines displayed a cell cycle block, caspase-dependent apoptosis, and dephosphorylation of key components of the signaling pathway. Autophagy was also induced in proliferating lymphocytes and in JURKAT and MOLT-4 cell lines. When autophagy was inhibited by 3-methyladenine or Bafilomycin A1, drug cytotoxicity was increased, indicating that autophagy is a protective mechanism. Therefore, our findings suggest that PI3K/Akt/mTOR inhibitors preserve lymphocyte viability. This is a valuable result to be taken into account when selecting drugs for targeted cancer therapy in order to minimize detrimental effects on immune function.

PI3K isoform inhibition associated with anti Bcr-Abl drugs shows in vitro increased anti-leukemic activity in Philadelphia chromosome-positive B-acute lymphoblastic leukemia cell lines

B-acute lymphoblastic leukemia (B-ALL) is a malignant disorder characterized by the abnormal proliferation of B-cell progenitors. Philadelphia chromosome-positive (Ph+) B-ALL is a subtype that expresses the Bcr-Abl fusion protein which represents a negative prognostic factor. Constitutive activation of the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) network is a common feature of B-ALL, influencing cell growth and survival. In the present study, we aimed to investigate the efficacy of PI3K isoform inhibition in B-ALL cell lines harboring the Bcr-Abl fusion protein.We studied the effects of anti Bcr-Abl drugs Imatinib, Nilotinib and GZD824 associated with PI3K isoform inhibitors. We used a panel of six compounds which specifically target PI3K isoforms including the pan-PI3K inhibitor ZSTK474, p110α BYL719 inhibitor and the dual p110γ/p110δ inhibitor IPI145. The effects of single drugs and of several drug combinations were analyzed to assess cytotoxicity by MTS assays, apoptosis and autophagy by flow cytometry and Western blot, as well as the phosphorylation status of the pathway.ZSTK474, BYL719 and IPI145 administered in combination with imatinib, nilotinib and GZD824 for 48 h, decreased cell viability, induced apoptosis and autophagy in a marked synergistic manner.These findings suggest that selected PI3K isoform inhibitors used in combination with anti Bcr-Abl drugs may be an attractive novel therapeutic intervention in Ph+ B-ALL.

Up-modulation of PLC-β2 reduces the number and malignancy of triple-negative breast tumor cells with a CD133+/EpCAM+ phenotype: a promising target for preventing progression of TNBC

Background

The malignant potential of triple negative breast cancer (TNBC) is also dependent on a sub-population of cells with a stem-like phenotype. Among the cancer stem cell markers, CD133 and EpCAM strongly correlate with breast tumor aggressiveness, suggesting that simultaneous targeting of the two surface antigens may be beneficial in treatment of TNBC. Since in TNBC-derived cells we demonstrated that PLC-β2 induces the conversion of CD133^high to CD133^low cells, here we explored its possible role in down-modulating the expression of both CD133 and EpCAM and, ultimately, in reducing the number of TNBC cells with a stem-like phenotype.

Methods

A magnetic step-by-step cell isolation with antibodies directed against CD133 and/or EpCAM was performed on the TNBC-derived MDA-MB-231 cell line. In the same cell model, PLC-β2 was over-expressed or down-modulated and cell proliferation and invasion capability were evaluated by Real-time cell assays. The surface expression of CD133, EpCAM and CD44 in the different experimental conditions were measured by multi-color flow cytometry immunophenotyping.

Results

A CD133⁺/EpCAM⁺ sub-population with high proliferation rate and invasion capability is present in the MDA-MB-231 cell line. Over-expression of PLC-β2 in CD133⁺/EpCAM⁺ cells reduced the surface expression of both CD133 and EpCAM, as well as proliferation and invasion capability of this cellular subset. On the other hand, the up-modulation of PLC-β2 in the whole MDA-MB-231 cell population reduced the number of cells with a CD44⁺/CD133⁺/EpCAM⁺ stem-like phenotype.

Conclusions

Since selective targeting of the cells with the highest aggressive potential may have a great clinical importance for TNBC, the up-modulation of PLC-β2, reducing the number of cells with a stem-like phenotype, may be a promising goal for novel therapies aimed to prevent the progression of aggressive breast tumors.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3592-y) contains supplementary material, which is available to authorized users.

Effects of Simulated Microgravity on the Morphology and Function of Neonatal Porcine Cell Clusters Cultured with and without Sertoli Cells

Human islet allografts are well known to induce full and sustained remission of hyperglycemia, with complete normalization of key metabolic parameters. Nevertheless, acquiring human islets, even from cadaveric human donor pancreases, remains a significant impediment to successful transplantation therapy for diabetes. To overcome this difficulty, neonatal porcine cell clusters (NPCCs) have been considered for human islet substitutes because they are easily obtained by collagenase digestion of the neonatal piglet pancreas. Currently, the major hurdle in using NPCCs for xenograft is the delay (time lag) in achieving the posttransplant normalization of blood glucose levels in animal diabetic recipients. The present work is the first attempt to evaluate whether incubation of NPCCs in simulated microgravity, in the presence or absence of Sertoli cells (SC), may reduce the maturation time lag of β-cells by differentiation acceleration in vitro, thereby expediting production, viability, and acquisition of functional competence of pretransplantation β-cell-enriched islets. Following a 3-day incubation period, NPCCs maintained in conventional culture, NPCCs incubated in simulated microgravity in the HARV biochamber, and NPCCs plus co-incubated SC in simulated microgravity were examined for viability, morphology, and insulin secretion. Results show that NPCCs grown alone in the HARV biochamber are superior in quality, both in terms of viability and functional competence, when compared to other culture pretreatment protocols. This finding strongly suggests that NPCC pretreatment in simulated microgravity may enhance the transplantation success of NPCCs in the diabetic recipient.

Reversal of the glycolytic phenotype of primary effusion lymphoma cells by combined targeting of cellular metabolism and PI3K/Akt/ mTOR signaling

PEL is a B-cell non-Hodgkin lymphoma, occurring predominantly as a lymphomatous effusion in body cavities, characterized by aggressive clinical course, with no standard therapy. Based on previous reports that PEL cells display a Warburg phenotype, we hypothesized that the highly hypoxic environment in which they grow in vivo makes them more reliant on glycolysis, and more vulnerable to drugs targeting this pathway. We established here that indeed PEL cells in hypoxia are more sensitive to glycolysis inhibition. Furthermore, since PI3K/Akt/mTOR has been proposed as a drug target in PEL, we ascertained that pathway-specific inhibitors, namely the dual PI3K and mTOR inhibitor, PF-04691502, and the Akt inhibitor, Akti 1/2, display improved cytotoxicity to PEL cells in hypoxic conditions. Unexpectedly, we found that these drugs reduce lactate production/extracellular acidification rate, and, in combination with the glycolysis inhibitor 2-deoxyglucose (2-DG), they shift PEL cells metabolism from aerobic glycolysis towards oxidative respiration. Moreover, the associations possess strong synergistic cytotoxicity towards PEL cells, and thus may reduce adverse reaction in vivo, while displaying very low toxicity to normal lymphocytes. Finally, we showed that the association of 2-DG and PF-04691502 maintains its cytotoxic and proapoptotic effect also in PEL cells co-cultured with human primary mesothelial cells, a condition known to mimic the in vivo environment and to exert a protective and pro-survival action. All together, these results provide a compelling rationale for the clinical development of new therapies for the treatment of PEL, based on combined targeting of glycolytic metabolism and constitutively activated signaling pathways.

The novel dual PI3K/mTOR inhibitor NVP-BGT226 displays cytotoxic activity in both normoxic and hypoxic hepatocarcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common lethal human malignancies worldwide and its advanced status is frequently resistant to conventional chemotherapeutic agents and radiation. We evaluated the cytotoxic effect of the orally bioavailable dual PI3K/mTOR inhibitor, NVP-BGT226, on a panel of HCC cell lines, since hyperactivated PI3K/Akt/mTOR signaling pathway could represent a biomolecular target for Small Inhibitor Molecules in this neoplasia. We analyzed the drug activity in both normoxia and hypoxia conditions, the latter playing often a relevant role in the induction of chemoresistance and angiogenesis.In normoxia NVP-BGT226 caused cell cycle arrest in the G0/G1 phase of the cell cycle, induced apoptosis and autophagy at low concentrations. Interestingly the drug inactivated p-Akt and p-S6 at < 10 nM concentration.In hypoxia NVP-BGT226 maintained its cytotoxic efficacy at the same concentration as documented by MTT assays and Western blot analysis. Moreover, the drug showed in hypoxia inhibitory properties against angiogenesis by lowering the expression of the transcription factor HIF-1α and of VEGF.Our results indicate that NVP-BGT226 has a potent cytotoxic effect on HCC cell lines also in hypoxia condition, thus emerging as a potential candidate for cancer treatment in HCC targeted therapy.

Triple Akt inhibition as a new therapeutic strategy in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder in which chemotherapy resistance and refractory relapses occur, with a poorer prognostic outcome.

Constitutively active PI3K/Akt/mTOR pathway is a common feature of T-ALL upregulating cell proliferation, survival and drug resistance. This pathway is currently under clinical trials with small molecules inhibitors (SMI).

To verify whether a multi-inhibition treatment against Akt protein could enhance the efficacy of individual drug administration and overcome drug resistance as well as to obtain a decrease in single drug concentration, we tested on T-ALL cell lines the effects of combined treatments with three Akt inhibitors with different mode of action, GSK690693, MK-2206 and Perifosine.

In cells with hyperactivated Akt, combined administration of the drugs displayed a significant synergistic and cytotoxic effect and affected PI3K/Akt/mTOR pathway at much lower concentration than single drug use. Highest synergistic effect for full inhibition of Akt was also related to the timing of every drug administration. Furthermore the triple treatment had greater efficacy in inducing cell cycle arrest in G₀/G₁ phase and both apoptosis and autophagy.

Targeting Akt as a key protein of PI3K/Akt/mTOR pathway with multiple drugs might represent a new and promising pharmacological strategy for treatment of T-ALL patients.

Abstract A34: Therapeutic potential of the novel mTOR inhibitor Torin-2 to overcome AKT reactivation in B-precursor acute lymphoblastic leukemia (B-pre ALL)

B-precursor acute lymphoblastic leukemia (B-pre ALL) is characterized by malignant proliferation and accumulation of early lymphoid precursor cells in the bone marrow, blood and lymphoid organs, due to acquired mutations in early B-cells. Around 20% of children and the majority of adults relapses after the treatment and the poor outcome following relapse did not significantly changed over the past twenty years. For this reason, many research efforts are currently devoted to the development of targeted therapies to limit side effects of chemotherapy and to increase treatment efficacy for poor prognosis patients.

Constitutively active phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling is a common feature of leukemia patients, where it negatively influences response to therapeutic treatments. Thus, targeting the PI3K/AKT /mTOR pathway is an attractive therapeutic strategy.

Rapamycin, an allosteric inhibitor of mTORC1, acutely inhibits mTORC1 but not mTORC2 activity. Prolonged suppression of mTORC1 also results in disruption of a negative feedback loop and consequently results in hyperphosphorylation of Akt through activation of IRS1 and PI3K.

mTOR inhibitors are currently in clinical trial for a range of hematological malignancies including ALL, mostly in combination with conventional chemotherapy.

RAD001, a mTORC1 inhibitor, has been shown to affect cell cycle progression and survival with a potentially relevant therapeutic efficacy. However, prolonged inhibition of mTORC1 often leads to AKT re-phosphorylation at Ser473which may counteract RAD001 activity.

A new class of ATP competitive mTOR inhibitors, such as Torin-2, have revealed that this new class of inhibitors potently targets mTORC1 and mTORC2. Together, these features have generated hope that the new generation of ATP-competitive mTOR inhibitors will exhibit broader clinical efficacy relative to the rapalogs.

We therefore hypothesized that dual inhibition of mTORC1 and mTORC2 by Torin-2 would provide a superior outcome in ALL as compared to inhibition of mTORC1 alone with RAD001 in B-pre-ALL. We tested the capability of Torin-2 to prevent AKT reactivation after mTORC1 and mTORC2 inhibition. Furthermore we explored if dual targeting of mTORC1 and AKT may achieve results similar to those obtained with Torin-2 alone.

We used a panel of B-pre-ALL to test the drugs by MTT Assay and Western Blotting after different time exposures of the cells. Cell cycle, apoptosis and autophagy were analyzed by flow cytometry, Western Blotting and fluorescent staining.

In all the B-pre-ALL cell lines Torin-2 showed a powerful cytotoxic activity, inhibiting the growth of each cell line in a dose-dependent manner, with an IC50 in the nanomolar range as assessed by MTT assays. The major proteins along the PI3K/AKT/mTOR signaling pathway where heavily dephosphorylated after 2 hrs of drug exposure.

This inhibition lasted up to at least 48 hrs at variance to RAD001, that already after 24 hrs was unable to prevent AKT reactivation. However the association of RAD001 with MK-2206, an allosteric AKT inhibitor, prevented AKT reactivation and reached a significant cytotoxicity.

Our data suggest an interesting cytotoxicity of Torin-2 in B-pre-ALL acting on both mTORC1 and mTORC2 as assessed by their substrate inhibition.

Torin-2 alone suppresses feedback activation of PI3K/AKT, whereas RAD001 requires the addition of MK-2206 to achieve the same efficacy. These two pharmacological options targeting PI3K/Akt/mTOR at different points of the signaling pathway cascade might represent a new therapeutic potential for treatment of B-pre-ALL patients.

Citation Format: Alice Cani, Carolina Simioni, Alberto M. Martelli, Giorgio Zauli, Silvano Capitani, Luca M. Neri. Therapeutic potential of the novel mTOR inhibitor Torin-2 to overcome AKT reactivation in B-precursor acute lymphoblastic leukemia (B-pre ALL). [abstract]. In: Proceedings of the AACR Special Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(17 Suppl):Abstract nr A34.

Abstract B46: Activity of the novel mTOR inhibitor Torin-2 in B-precursor acute lymphoblastic leukemia and its therapeutic potential to prevent AKT reactivation

mTOR is a highly conserved and widely expressed serine/threonine kinase, that is a member of the phosphatidylinositol-3 kinase–like kinase (PIKK) family. mTOR plays a pivotal role in the PI3K/Akt/mTOR signaling pathway, which senses growth factor and serves as a central regulator of fundamental cellular processes such cell growth/apoptosis, autophagy, translation, and metabolism. Hyperactivation of this pathway through loss of negative regulators, such as PTEN, or mutational activation of receptor tyrosine kinases of phosphoinositide 3-kinase (PI3K) is a frequent occurrence in leukemia patients, where it negatively influences response to therapeutic treatments.

In B-precursor acute lymphoblastic leukemia (B-pre ALL) many research efforts are currently devoted to the development of targeted therapies to limit side effects of chemotherapy and to increase treatment efficacy for poor prognosis patients, i.e. poor outcome following relapse.

Thus, targeting the PI3K/AKT /mTOR pathway is an attractive therapeutic strategy. Numerous inhibitors targeting these kinases are currently undergoing clinical evaluation in hematological malignancies including ALL, mostly in combination with conventional chemotherapy.

Prolonged suppression of mTORC1 also results in disruption of a negative feedback loop and often results in re/hyper-phosphorylation of Akt through activation of IRS1 and PI3K, which may counteract rapalogs activity.

A new class of ATP-competitive mTOR inhibitors, such as Torin-2, has revealed that these inhibitors potently targets mTORC1 and mTORC2. Together, these features have generated hope that this new generation of inhibitors will exhibit broader clinical efficacy when compared to the rapalogs.

We therefore hypothesized that dual inhibition of mTORC1 and mTORC2 by Torin-2 would provide a superior outcome in ALL as compared to inhibition of mTORC1 alone with RAD001 in B-pre-ALL. We tested the capability of Torin-2 to prevent AKT reactivation after mTORC1 and mTORC2 inhibition. Furthermore we explored if dual targeting of mTORC1 and AKT may achieve results similar to those obtained with Torin-2 alone.

Drugs cytotoxic activity were analyzed in a panel of B-pre-ALL cells by MTT Assay and Western Blotting at different time points. Cell cycle, apoptosis and autophagy were analyzed by flow cytometry, Western Blotting and fluorescent staining.

In all the B-pre-ALL cell lines Torin-2 showed a powerful cytotoxic activity, inhibiting the growth of each cell line in a dose-dependent manner, with an IC50 in the nanomolar range as assessed by MTT assays. The major proteins along the PI3K/AKT/mTOR signaling pathway where heavily dephosphorylated after 2 hrs of drug exposure.

This inhibition lasted up to at least 48 hrs at variance to RAD001, that already after 24 hrs was unable to prevent AKT reactivation. However the association of RAD001 with MK-2206, an allosteric AKT inhibitor, prevented AKT reactivation and reached a significant cytotoxicity.

These data suggest an interesting cytotoxicity of Torin-2 in B-pre-ALL acting on both mTORC1 and mTORC2 as assessed by their specific substrate inhibition.

Feedback activation of PI3K/AKT was suppressed by Torin-2 alone, whereas RAD001 required the addition of MK-2206 to achieve the same efficacy.

These two pharmacological strategies targeting PI3K/Akt/mTOR at different points of the signaling pathway cascade might represent a new therapeutic option in B-pre-ALL patients also preventing Akt reactivation.

Citation Format: Carolina Simioni, Alice Cani, Alberto M. Martelli, Giorgio Zauli, Silvano Capitani, Luca M. Neri. Activity of the novel mTOR inhibitor Torin-2 in B-precursor acute lymphoblastic leukemia and its therapeutic potential to prevent AKT reactivation. [abstract]. In: Proceedings of the AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; Sep 14-17, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(7 Suppl):Abstract nr B46.

High nuclear level of Vav1 is a positive prognostic factor in early invasive breast tumors: a role in modulating genes related to the efficiency of metastatic process

Vav1 is one of the signalling proteins normally restricted to hematopoietic cells that results ectopically expressed in solid tumors, including breast cancer. By immunohistochemical analysis on TMAs containing invasive breast tumor from patients without lymph node involvement, we have found that Vav1 is expressed in almost all investigated cancers and shows a peculiar localization inside the nucleus of tumor cells. High amounts of nuclear Vav1 are positively correlated with low incidence of relapse, regardless phenotype and molecular subtype of breast neoplasia. In particular, Kaplan-Meier plots showed an elevated risk of distant metastasis in patients with low Vav1 expression compared with patients with high Vav1 expression in their tumors. Experiments performed with breast tumor-derived cells indicated that Vav1 negatively modulates their invasiveness in vitro and their metastatic efficiency in vivo, possibly by affecting the expression of genes involved in invasion and/or metastasis of breast tumors. Since the high heterogeneity of breast tumors makes difficult to predict the evolution of early breast neoplasias, the evaluation of nuclear Vav1 levels may help in the characterization and management of early breast cancer patients. In particular, Vav1 may serve as a prognostic biomarker and a target for new therapies aimed to prevent breast cancer progression.

In triple negative breast tumor cells, PLC-β2 promotes the conversion of CD133high to CD133low phenotype and reduces the CD133-related invasiveness

Background

Beyond its possible correlation with stemness of tumor cells, CD133/prominin1 is considered an important marker in breast cancer, since it correlates with tumor size, metastasis and clinical stage of triple-negative breast cancers (TNBC), to date the highest risk breast neoplasia.

Methods

To study the correlation between the levels of CD133 expression and the biology of breast-derived cells, CD133^low and CD133^high cell subpopulations isolated from triple negative MDA-MB-231 cells were compared in terms of malignant properties and protein expression.

Results

High expression of CD133 characterizes cells with larger adhesion area, lower proliferation rate and reduced migration speed, indicative of a less undifferentiated phenotype. Conversely, when compared with CD133^low cells, CD133^high cells show higher invasive capability and increased expression of proteins involved in metastasis and drug-resistance of breast tumors. Among the signalling proteins examined, PLC-β2 expression inversely correlates with the levels of CD133 and has a role in inducing the CD133^high cells to CD133^low cells conversion, suggesting that, in TNBC cells, the de-regulation of this PLC isoform is responsible of the switch from an early to a mature tumoral phenotype also by reducing the expression of CD133.

Conclusions

Since CD133 plays a role in determining the invasiveness of CD133^high cells, it may constitute an attractive target to reduce the metastatic potential of TNBC. In addition, our data showing that the forced up-regulation of PLC-β2 counteracts the invasiveness of CD133-positive MDA-MB-231 cells might contribute to identify unexplored key steps responsible for the TNBC high malignancy, to be considered for potential therapeutic strategies.

Targeting the PI3K/Akt/mTOR signaling pathway in B-precursor acute lymphoblastic leukemia and its therapeutic potential

B-precursor acute lymphoblastic leukemia (B-pre ALL) is a malignant disorder characterized by the abnormal proliferation of B-cell progenitors. The prognosis of B-pre ALL has improved in pediatric patients, but the outcome is much less successful in adults. Constitutive activation of the phosphatidylinositol 3-kinase (PI3K), Akt and the mammalian target of rapamycin (mTOR) (PI3K/Akt/mTOR) network is a feature of B-pre ALL, where it strongly influences cell growth and survival. RAD001, a selective mTORC1 inhibitor, has been shown to be cytotoxic against many types of cancer including hematological malignancies. To investigate whether mTORC1 could represent a target in the therapy of B-pre ALL, we treated cell lines and adult patient primary cells with RAD001. We documented that RAD001 decreased cell viability, induced cell cycle arrest in G0/G1 phase and caused apoptosis in B-pre ALL cell lines. Autophagy was also induced, which was important for the RAD001 cytotoxic effect, as downregulation of Beclin-1 reduced drug cytotoxicity. RAD001 strongly synergized with the novel allosteric Akt inhibitor MK-2206 in both cell lines and patient samples. Similar results were obtained with the combination CCI-779 plus GSK 690693. These findings point out that mTORC1 inhibitors, either as a single agent or in combination with Akt inhibitors, could represent a potential therapeutic innovative strategy in B-pre ALL.

Hiv-1 tat protein suppresses the nerve growth-factor (ngf)-mediated differentiation of PC12 rat pheochromocytoma cell-line

In order to evaluate the effect of the regulatory human immunodeficiency virus-type 1 (HIV-1) Tat protein on the process of neuronal differentiation, two tat-transfected and mock-transfected PC12 cell lines were cultured in the absence or presence of 100-1000 ng/ml of nerve growth factor (NGF). As expected, NGF was able to induce a clearcut morphological differentiation of mock-transfected PC12 into sympathetic-like neurons, also reducing the percentage of cells in S phase. On the other hand, NGF was unable to reduce the percentage of PC12-tat cells in S phase and/or to induce their neuronal differentiation. Only the addition in culture of 5 mu g/ml neutralizing anti-Tat antibody plus 1000 ng/ml NGF was effective in decreasing the percentage of PC12-tat in S phase and inducing partial signs of neuronal differentiation in serum-free cultures. The ability of Tat protein to suppress the neuronal differentiation pathway controlled by NGF further contribute to the definition of its role in tumor promotion during the course of HTV-1 disease.

Cytotoxic activity of the novel Akt inhibitor, MK-2206, in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder arising from T-cell progenitors. T-ALL accounts for 15% of newly diagnosed ALL cases in children and 25% in adults. Although the prognosis of T-ALL has improved, due to the use of polychemotherapy schemes, the outcome of relapsed/chemoresistant T-ALL cases is still poor. A signaling pathway that is frequently upregulated in T-ALL, is the phosphatidylinositol 3-kinase/Akt/mTOR network. To explore whether Akt could represent a target for therapeutic intervention in T-ALL, we evaluated the effects of the novel allosteric Akt inhibitor, MK-2206, on a panel of human T-ALL cell lines and primary cells from T-ALL patients. MK-2206 decreased T-ALL cell line viability by blocking leukemic cells in the G(0)/G(1) phase of the cell cycle and inducing apoptosis. MK-2206 also induced autophagy, as demonstrated by an increase in the 14-kDa form of LC3A/B. Western blotting analysis documented a concentration-dependent dephosphorylation of Akt and its downstream targets, GSK-3α/β and FOXO3A, in response to MK-2206. MK-2206 was cytotoxic to primary T-ALL cells and induced apoptosis in a T-ALL patient cell subset (CD34(+)/CD4(-)/CD7(-)), which is enriched in leukemia-initiating cells. Taken together, our findings indicate that Akt inhibition may represent a potential therapeutic strategy in T-ALL.

Abstract 3750: The novel Akt inhibitor MK-2206, is cytotoxic in T-cell acute lymphoblastic leukemia: Therapeutic implications

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive neoplastic disorder arising within the thymus from the clonal proliferation of T-cell precursors. T-ALL accounts for 15% of ALL cases in children and 25% in adults. Although the prognosis of T-ALL has improved, due to the use of intensive polychemotherapy schemes, the outcome of relapsed and chemoresistant T-ALL is still poor, especially in adults, with a 35-40% survival at 5 years. Therefore, efforts are being made to develop targeted therapies against deregulated signaling cascades that sustain T-ALL cell proliferation, survival, and drug-resistance. A signaling pathway that is frequently upregulated in T-ALL, is the PI3K/Akt/mTOR network. To explore whether or not Akt could represent a potential target for therapeutic intervention in T-ALL, we evaluated the effects of the novel allosteric Akt inhibitor, MK-2206, on a panel of human T-ALL cell lines (MOLT-4, CEM, drug-resistant CEM) and primary cells from T-ALL patients, characterized by pathway upregulation. MK-2206 decreased T-ALL cell line viability as documented by MTT assays. IC50 for MK-2206 ranged from 1.0 to 4.8 μM at 48 hours. The drug was effective against drug-resistant CEM cells, overexpressing 170-kDa P-glycoprotein. MK-2206 blocked leukemic cells in the G1 phase of the cell cycle and induced caspase-dependent apoptotic cell death, as documented by Annexin V/propidium iodide staining and western blot analysis. In CEM cells, MK-2206 induced autophagy, as demonstrated by an increase in the 14-kDa form of LC3A/B. Western blotting documented a concentration-dependent dephosphorylation of Akt and its downstream targets, GSK-3β and FOXO3A, in response to MK-2206. mTORC1 downstream targets were also efficiently dephosphorylated by MK-2206, including p70S6K and 4E-BP1. MK-2206 decreased mTORC2 activity, as indicated by the downregulation of Ser 2481 p-mTOR levels, a readout for mTORC2 activity In MOLT-4 and CEM cells, MK-2206 strongly synergized (combination index: 0.1-0.33) with doxorubicin. Moreover, MK-2206 dephosphorylated Akt and induced apoptosis in a T-ALL patient cell subset (CD34+/CD4−/CD7−) which is enriched in leukemia initiating cells. Our findings indicate that Akt inhibition, either alone or in combination with chemotherapeutic drugs, represents a potential therapeutic target in T-ALL cells that require upregulation of the PI3K/Akt/mTOR signaling pathway for their proliferation and survival.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3750. doi:1538-7445.AM2012-3750

Abstract 3736: The mTOR inhibitor, RAD001, displays higher cytotoxicity in leukemias with hyperactivated PI3K/AKT/mTOR pathway

Acute myelogenous leukemia (AML) is a disease resulting from the clonal expansion and accumulation of hematopoietic stem cells arrested at various stages of development. B-cell Acute lymphoblastic leukemia (B-ALL) is a form of leukemia characterized by lymphoblast abnormal increase. B-ALL is the most common form of cancer in childhood with a peak of incidence at 2-5 years of age, and another peak in the elderly. The overall cure rate in children is about 80%, and about 38% to 60% of adults have long-term disease-free survival. Although the prognosis of AML and ALL has improved in the last decades, the outcome of relapsed and chemoresistant AML and ALL is still poor, especially in adults, with only a 35-40% survival at 5 years. Therefore, major efforts are being made to develop rationally targeted therapies against alterated signaling cascades that sustain AML and ALL cell proliferation, survival, and drug-resistance. A signaling pathway that is frequently upregulated in AML and ALL is the PI3K/Akt/mTOR network. To explore whether this pathway could represent a potential pharmacological target in AML and ALL, we evaluated the effects of the mTOR inhibitor, RAD001, on the HL60 AML cell line and on the SEM B-ALL cell line.RAD001decreased viability in AML and ALL cell lines, as demonstrated by MTT experiments. The values of IC50 at 24 and 48 hours in HL60 cell line was 8μM, while in SEM cell line, that displays an hyperactivation of the PI3K/Akt/mTOR pathway, the IC50 range was from 4,7 to 6,8 μM, thus showing an higher sensitivity of this cell line to this targeted therapy. As documented by Western Blotting, RAD001 showed a concentration-dependent induction of apoptosis with a relevant increment of PARP, Caspase 3, 8 and 9 cleavage in both cell lines. The ALL cell line SEM, with hyperactivated PI3K/Akt/mTOR pathway, displayed a much higher Caspase and PARP cleavage dependent apoptosis.PI3K/Akt/mTOR downstream targets were also partially dephosphorylated by RAD001, in particular GSK3β and 4E-BP1. RAD001 induced no significant changes in Akt dephosphorylation in HL60 and SEM cell lines, and this is in agreement with several reports showing no relevant changes in the phosphorylation of Akt. The cells always expressed unchanged total Akt. This indicates that PI3K/Akt/mTOR inhibition could be an attractive target to develop innovative therapeutic strategies directed towards AML and ALL leukemia cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3736. doi:1538-7445.AM2012-3736

Vav1 in differentiation of tumoral promyelocytes

The multidomain protein Vav1, in addition to promote the acquisition of maturation related properties by normal hematopoietic cells, is a key player in the ATRA- and PMA-induced completion of the differentiation program of tumoral myeloid precursors derived from APL. This review is focussed on the role of Vav1 in differentiating promyelocytes, as part of interconnected networks of functionally related proteins ended to regulate different aspects of myeloid maturation. The role of Vav1 in determining actin cytoskeleton reorganization alternative to the best known function as a GEF for small G proteins is discussed, as well as the binding of Vav1 with cytoplasmic and nuclear signaling molecules which provides a new perspective in the modulation of nuclear architecture and activity. In particular, new hints are provided on the ability of Vav1 to determine the nuclear amount of proteins implicated in modulating mRNA production and stability and in regulating the ATRA-dependent protein expression also by direct interaction with transcription factors known to drive the ATRA-induced maturation of myeloid cells. The reviewed findings summarize the major advances in the understanding of additional, non conventional functions connected with the vast interactive potential of Vav1.

Nuclear proteome analysis reveals a role of Vav1 in modulating RNA processing during maturation of tumoral promyelocytes

Vav1 is a key molecule in the ATRA-induced acquisition of a mature phenotype by tumoral myeloid precursors. Since ATRA acts throughout events that require extensive changes of nuclear architecture and activity and considering that Vav1 accumulates inside the nuclear compartment of differentiating APL-derived cells, the possible role of this protein in modulating the nuclear proteome was investigated. Membrane-depleted nuclei purified from NB4 cells induced to differentiate with ATRA in the presence of forcedly down-modulated Vav1 were subjected to 2D-DIGE followed by mass spectra analysis. The obtained data demonstrated that, in NB4 cells treated with ATRA, Vav1 is involved in determining the nuclear amount of proteins involved in molecular complexes with DNA and may participate to RNA processing by carrying in the nucleus molecules involved in modulating mRNA production and stability, like hnRNPs and SR proteins. Our results provide the first evidence that, at least in maturation of tumoral myeloid precursors, Vav1 is part of interconnected networks of functionally related proteins ended to regulate different aspects of gene expression. Since defects in mRNA processing are common in tumor development, our data suggest that Vav1 is a potential target molecule for developing new anti-cancer strategies.

In Memoriam of Prof. Giovanni Mazzotti

In Memoriam of Prof. Giovanni Mazzotti

Mass spectrometry-based identification of Y745 of Vav1 as a tyrosine residue crucial in maturation of acute promyelocytic leukemia-derived cells

Vav1, whose physiological expression is restricted to hematopoietic system, is one of the signaling proteins up-regulated by all-trans retinoic acid (ATRA) in acute promyelocytic leukemia (APL)-derived precursors, in which it promotes the overcoming of the differentiation blockade. High levels of tyrosine phosphorylated Vav1 accumulate in differentiating APL-derived cells, suggesting that one or more Vav1 tyrosine residues are involved in neutrophil differentiation of tumoral promyelocytes. Here, we have found that phosphorylation of Vav1 Y174, that is known to regulate Vav1 activity in mature neutrophils, is up-regulated by ATRA in NB4 cells. Nevertheless, this tyrosine residue does not seem crucial for the agonist-induced phenotypical differentiation of APL-derived cells. Mass spectrometry analysis performed on Vav1 from differentiating NB4 cells allowed to identify the highly conserved Y745 residue as a phosphorylated tyrosine that plays crucial roles in the completion of the maturation program of this cell line. In fact, the overexpression of a mutated form of Vav1, in which Y745 was replaced with a phenylalanine, significantly reduced the ATRA-induced CD11b expression and essentially abrogated the differentiation-related acquisition of the migratory capability. Even though the intracellular signaling involving Vav1 phosphorylated in Y745 is unknown, the identification of a tyrosine residue essential for differentiation of tumoral precursors may constitute the basis to identify new specific targets for differentiation therapy of APL.

Semen quality of male idiopathic infertile smokers and nonsmokers: an ultrastructural study

This retrospective study was aimed at evaluating the effects of cigarette consumption on semen parameters in a group of men with idiopathic infertility. The semen quality of 2 groups of men with idiopathic infertility, smokers (n = 118) and nonsmokers (n = 153), were compared. Conventional semen analysis was performed and sperm morphology was assessed by transmission electron microscopy (TEM). TEM data were elaborated by means of a mathematical formula based on a Bayesian technique able to furnish a fertility index (FI), and the percentages of sperm apoptosis, necrosis, and immaturity. Values of normality recommended by World Health Organization guidelines were used as a control for conventional semen analysis, and values from sperm of 25 men of proven fertility were used for TEM indices. Infertile smoker and nonsmoker patients showed similar sperm parameters, although sperm motility and TEM analysis values in both groups were significantly impaired compared with controls. Smoker patients were then classified as mild (>or=1 and <or=10 cigarettes/d), moderate (>10 and <20 cigarettes/day), or heavy smokers (>or=20 cigarettes/d). Sperm concentration and FI were significantly (P < .05) different among the 3 considered smoker classes. Comparing the pairs of smoker classes, sperm concentration and FI in heavy smokers were significantly lower (P < .05) than that observed in mild smoker and nonsmoker groups. Although semen quality in males with idiopathic infertility seems not to be dramatically affected by cigarette consumption, heavy smokers show significantly lower sperm concentration and FI: another strong reason to stop smoking.

Phytothermotherapy: a possible complementary therapy for fibromyalgia patients

OBJECTIVE

It is a traditional practice in the Alpine region of Trentino and Alto Adige (Italy) to use phytothermotherapeutic treatment with fermenting grass ("hay baths") for rheumatic diseases. However, despite its long history and popularity, a clinical validation of the efficacy and tolerability of the treatment has yet to be found in current literature. Fibromyalgia syndrome (FMS) is characterised by generalised musculoskeletal pain, high tender point counts, sleep disturbance, fatigue, headaches, irritable bowel syndrome, frequent psychological distress and depressed mood. There is no standard therapy regime for FMS and the variety of medical treatments used have given limited benefits. The aim of this study was to assess the efficacy and tolerability of a cycle of phytothermotherapy through a single-blind, controlled, randomised trial, in patients with primary FMS.

METHODS

Fifty-six patients with primary FMS according to the ACR criteria were randomly allocated to two groups: 30 were submitted to phytothermotherapy at the thermal resort of Garniga Terme (Trento, Italy) and the other 26 were considered as controls. All patients were evaluated by FIQ, Tender Points Count, HAQ and AIMS1 at baseline, after 10 days, then after 12 and 24 weeks.

RESULTS

Patients submitted to phytothermotherapy showed visible and significant improvement of all evaluation parameters at the end of the treatment, which persisted during the follow-up period. No significant difference was found in the control group. Regarding the tolerability, none of the patients presented side effects.

CONCLUSIONS

Our results suggest the efficacy and the tolerability of phytothermotherapy in patients with primary FMS.

Nuclear protein kinase C isoforms and apoptosis

The process of apoptosis is regulated at multiple levels through phosphorylation by several different protein kinases. The protein kinase C (PKC) family of isozymes have been shown to exert both inhibitory and stimulatory influences on apoptosis. During the apoptotic process phosphorylative events are known to occur also at the nuclear level. Evidence suggests that PKC isoforms play a key role in some steps that lead to nuclear disassembly during the execution phase of apoptosis. This review highlights the recent progress made in determining the roles played by individual PKC nuclear isoforms in the control of apoptosis.

Familial non-medullary thyroid carcinoma displays the features of clinical anticipation suggestive of a distinct biological entity

Non-medullary thyroid carcinoma (NMTC) is mostly sporadic, but familial clustering is described. We aimed to compare the features of patients with sporadic and familial NMTC (FNMTC) patients and to assess whether FNMTC patients with parent-child relationship exhibit the 'anticipation' phenomenon (earlier age at disease onset and increased severity in successive generations). Among 300 NMTCs followed in the Section of Endocrinology (University of Siena, Italy), 34 (11.3%) patients, all with the papillary histotype, (16 kindred), met the criteria of FNMTC. Twenty-seven of them (79.4%) exhibited a parent-child relationship and seven (20.6%) a sibling relationship. These patients were compared with 235 patients with sporadic papillary thyroid cancer (PTCs). To analyze the features of FNMTC of the first and second generations, we cumulated the series of Siena with 32 additional FNMTC patients (15 kindred) from the Department of Endocrinology-Endocrine Oncology, Thessaloniki, Greece. Significant difference between sporadic PTC and FNMTC patients included more frequent tumor multifocality (P=0.001) and worse final outcome in FNMTC patients (P=0.001). Among 47 FNMTC with parent-child relationship, we found an earlier age at disease presentation (P<0.0001), diagnosis (P<0.0001), and disease onset (P=0.04) in the second generation when compared with the first generation. Patients in the second generation were more frequently males (P=0.02); their tumors were more frequently multifocal (P=0.003) and bilateral (P=0.01), had higher rate of lymph node metastases at surgery (P=0.02) and worse outcome (P=0.04) when compared with the first generation. In conclusion, FNMTC displays the features of clinical 'anticipation' with the second generation acquiring the disease at an earlier age and having more advanced disease at presentation.

Nuclear translocation of active AKT is required for erythroid differentiation in erythropoietin treated K562 erythroleukemia cells

Erythroid differentiation of human erythroleukemia cell line K562 induced by erythropoietin is a complex process that involves modifications at nuclear level, including nuclear translocation of phosphatidyl-inositol 3-kinase. In this work we show that erythropoietin stimulation of K562 cells can induce nuclear translocation of active Akt, a downstream molecule of the phosphatidyl-inositol 3-kinase signaling pathway. Akt shows a peak of activity in whole cell homogenates at earlier stage when compared to the nucleus, which shows a peak delayed of 10 min. Akt increases its intranuclear amount and activity rapidly and transiently in response to EPO. Almost all Akt kinase that translocates to the nucleus shows a marked phosphorylation on serine 473. Nuclear enzyme translocation is blocked by the phosphatidyl-inositol 3-kinase inhibitor Ly294002 or Wortmannin. The specific Akt pharmacological inhibitor VI, VII and VIII that act as blocking enzyme activation inhibited translocation as well, whereas Akt inhibitor IX, that inhibits Akt activity, did not block Akt nuclear translocation. When cells were treated by means of siRNA sequences or with the Akt inhibitors the differentiation process was arrested, thus showing the requirement of the nuclear translocation of the active enzyme to differentiate. These findings strongly suggest that the intranuclear translocation of active Akt kinase represents an important step in the signaling pathway that mediates erythropoietin-induced erythroid differentiation.

MDM2 antagonist Nutlin-3 suppresses the proliferation and differentiation of human pre-osteoclasts through a p53-dependent pathway

Exposure of human pre-osteoclasts to the MDM2 antagonist Nutlin-3 activated the p53 pathway and significantly decreased the entry of pre-osteoclasts in the S phase in response to RANKL. Moreover, repeated exposure to Nutlin-3 suppressed osteoclastic differentiation, without affecting cell survival at any culture time.

INTRODUCTION

The p53 oncosuppressor coordinates an intracellular network involved in protection from malignant transformation and cell cycle control; its activation is tightly regulated by the murine double minute 2 (MDM2) gene and p53-MDM2 interaction can be disrupted by selective small molecule inhibitors, the Nutlins. Although the ability of Nutlins to suppress the growth of wildtype p53 tumors has been clearly established, their biological activity in normal cells and tissues has not been extensively studied.

MATERIALS AND METHODS

Peripheral blood mononuclear cell pre-osteoclasts were cultured with macrophage-colony stimulating factor (M-CSF) + RANKL or co-cultured with SaOS-2 osteosarcoma cells in the presence of IL-1beta to induce osteoclastic differentiation. Cell cycle was analyzed by BrdU incorporation. The degree of osteoclastic differentiation was monitored at different culture times by TRACP and DAPI staining, as well as by TRACP-5b ELISA. Finally, the role of p53 in mediating the biological activity of Nutlin-3 was studied using specific siRNA.

RESULTS

Exposure of human pre-osteoclasts to RANKL induced an early (24 h) increase in the percentage of cells in the S phase, followed by the exit from the cell cycle at later time-points. The simultaneous addition of Nutlin-3 and RANKL dose-dependently decreased the percentage of pre-osteoclasts in the S phase and induced a rapid accumulation of p53 protein coupled with the induction of p53 target genes. Unexpectedly, the administration of Nutlin-3 to pre-osteoclasts at early culture times significantly suppressed the final output of osteoclasts at day 14 of culture. The role of p53 in mediating this biological activity of Nutlin-3 was underscored by gene knockdown experiments, in which the anti-osteoclastic activity of Nutlin-3 was significantly counteracted by siRNA specific for p53. Nutlin-3 also significantly decreased the formation of osteoclasts in a co-culture system of SaOS-2 osteosarcoma and pre-osteoclastic cells.

CONCLUSIONS

These findings indicate that Nutlin-3 abrogates both pre-osteoclastic proliferation and differentiation through a p53-dependent pathway and may have therapeutic implications for those neoplastic diseases characterized by an abnormal osteoclastic activity.

Sperm aneuploidies and low progressive motility

BACKGROUND

Patients with poor semen quality show increased sperm disomy and diploidy rates. Oligozoospermia and teratozoospermia are known to influence sperm aneuploidy, but there is still a debate about whether aneuploidies are associated with reduced motility.

METHODS

Ejaculates from a large group of patients were examined by light microscopy to evaluate sperm concentration, motility and morphology, and by fluorescence in-situ hybridization (FISH) to analyse the presence of aneuploidies. Statistical analysis was performed to compare differences and to evaluate the relationship between sperm aneuploidy rate and semen quality.

RESULTS

Five groups were established following the motility parameter, and total aneuploidy rates were statistically significantly higher in the groups where motility was <30% compared to the controls. A homogeneous group of men with asthenozoospermia showed higher FISH values compared to control data, although the difference was not statistically significant. Motility and sperm morphology were each found to be statistically related to aneuploidy using a multiple linear regression analysis, whereas sperm concentration was only related to aneuploidy by the equation of a hyperbolic curve.

CONCLUSIONS

In conclusion, biological and statistical data from the present research support the idea that the presence of aneuploidies could also be associated with reduced sperm motility.

Ethanolic extract from Hemidesmus indicus (Linn) displays otoprotectant activities on organotypic cultures without interfering on gentamicin uptake

The ethanolic extract from Hemidesmus indicus (Linn) (Apocynaceae) (Hie) was studied for its otoprotective effects in ex vivo rat organotypic model of gentamicin (GM) toxicity. In organ of Corti organotypic cultures (OC), GM can induce a fast dose-dependent apoptosis of hair cells (HC), both external and internal. We found that, after coadministration of GM and Hie to organotypic cultures, the extract was able to significantly counteract this toxic effect on HC, at the concentration of 25 and 50microg/ml. Interestingly, at these concentrations the extract was present in the cell medium at a concentration 1.6- and 3.3-fold lower than GM, suggesting its otoprotective activity could not merely due to an aspecific inhibition of GM entry. To support this hypothesis, we evaluated the amount of GM present in organotypic cultures after the coadministration of 1.5mg/ml GM and Hie, and found no significant reduction of GM uptake in the presence of 100microg/ml Hie. These data suggest the otoprotective action of Hie derives from specific inhibition of the apoptotic routine induced by GM treatment.

Phospholipase C-β2 promotes mitosis and migration of human breast cancer-derived cells

Like most human neoplasm, breast cancer has aberrations in signal transduction elements that can lead to increased proliferative potential, apoptosis inhibition, tissue invasion and metastasis. Due to the high heterogeneity of this tumor, currently, no markers are clearly associated with the insurgence of breast cancer, as well as with its progression from in situ lesion to invasive carcinoma. We have recently demonstrated an altered expression of the beta2 isoform of the phosphoinositide-dependent phospholipase C (PLC) in invasive breast tumors with different histopathological features. In primary breast tumor cells, elevated amounts of this protein are closely correlated with a poor prognosis of patients with mammary carcinoma, suggesting that PLC-beta2 may be involved in the development and worsening of the malignant phenotype. Here we demonstrate that PLC-beta2 may improve some malignant characteristics of tumor cells, like motility and invasion capability, but it fails to induce tumorigenesis in non-transformed breast-derived cells. We also report that, compared with the G(0)/G(1) phases of the cell cycle, the cells in S/G(2)/M phases show high PLC-beta2 expressions that reach the greatest levels during the late mitotic stages. In addition, even if unable to modify the proliferation rate and the expression of cell cycle-related enzymes of malignant cells, PLC-beta2 may promote the G(2)/M progression, a critical event in cancer evolution. Since phosphoinositides, substrates of PLC, are involved in regulating cytoskeleton architecture, PLC-beta2 in breast tumor cells may mediate the modification of cell shape that characterizes cell division, motility and invasion. On the basis of these data, PLC-beta2 may constitute a molecular marker of breast tumor cells able to monitor the progression to invasive cancers and a target for novel therapeutic breast cancer strategies.

PLC-beta2 activity on actin-associated polyphosphoinositides promotes migration of differentiating tumoral myeloid precursors

During both maturation and function, neutrophils are subjected to reorganization of the actin cytoskeleton. Among the molecules that influence cytoskeletal architecture, the amount and subcellular localization of phosphoinositides, regulated by specific kinases and phosphatases, may play a crucial role. In neutrophils, PLC-beta2 is a major phosphoinositide-dependent phospholipase C isoform activated in response to chemoattractants, even though its role in the modifications of cell morphology and motility that occur during the inflammatory process has not been fully elucidated. In APL-derived promyelocytes induced to complete their maturation program, we have found that the expression levels of PLC-beta2 positively correlate with the degree of the reached neutrophil differentiation. Here, we demonstrate that PLC-beta2 modulates the migration capability of promyelocytes induced to differentiate with ATRA. In differentiating cells, the association of PLC-beta2 with actin, mediated by the PH domain, seems crucial for catalytic activity. We conclude that phosphodiesterase activity of PLC-beta2 on the actin-associated PIP2 may be responsible, by modifying the phosphoinositide pools, for the modifications of cytoskeleton architecture that take place during motility of differentiating promyelocytes.