ATF6 supports lysosomal function in tumor cells to enable ER stress-activated macroautophagy and CMA: impact on mutant TP53 expression

The inhibition of the unfolded protein response (UPR), which usually protects cancer cells from stress, may be exploited to potentiate the cytotoxic effect of drugs inducing ER stress. However, in this study, we found that ER stress and UPR activation by thapsigargin or tunicamycin promoted the lysosomal degradation of mutant (MUT) TP53 and that the inhibition of the UPR sensor ATF6, but not of ERN1/IRE1 or EIF2AK3/PERK, counteracted such an effect. ATF6 activation was indeed required to sustain the function of lysosomes, enabling the execution of chaperone-mediated autophagy (CMA) as well as of macroautophagy, processes involved in the degradation of MUT TP53 in stressed cancer cells. At the molecular level, by pharmacological and genetic approaches, we demonstrated that the inhibition of ATF6 correlated with the activation of MTOR and with TFEB and LAMP1 downregulation in thapsigargin-treated MUT TP53 carrying cells. We hypothesize that the rescue of MUT TP53 expression by ATF6 inhibition, could further activate MTOR and maintain lysosomal dysfunction, further inhibiting MUT TP53 degradation, in a vicious circle. The findings of this study suggest that the presence of MUT TP53, which often exerts oncogenic properties, should be considered before approaching treatments combining ER stressors with ATF6 inhibitors against cancer cells, while it could represent a promising strategy against cancer cells that harbor WT TP53.

The inhibition of IRE1alpha/XBP1 axis prevents EBV-driven lymphomagenesis in NSG mice

IMPORTANCE

The novelty of this study lies in the fact that it shows that IRE1 alpha endoribonuclease inhibition by 4μ8C was able to counteract Epstein-Barr virus-driven lymphomagenesis in NOD SCID gamma mice and prevent B-cell immortalization in vitro, unveiling that this drug may be a promising therapeutic approach to reduce the risk of post-transplant lymphoproliferative disorders (PTLD) onset in immune-deficient patients. This hypothesis is further supported by the fact that 4μ8C impaired the survival of PTLD-like cells derived from mice, meaning that it could be helpful also in the case in which there is the possibility that these malignancies have begun to arise.

HHV-6A Infection of Papillary Thyroid Cancer Cells Induces Several Effects Related to Cancer Progression

Recent studies have shown that thyrocytes are permissive to HHV-6A infection and that the virus may contribute to the pathogenesis of autoimmune thyroiditis. Thyroid autoimmune diseases increase the risk of papillary cancer, which is not surprising considering that chronic inflammation activates pathways that are also pro-oncogenic. Moreover, in this condition, cell proliferation is stimulated as an attempt to repair tissue damage caused by the inflammatory process. Interestingly, it has been reported that the well-differentiated papillary thyroid carcinoma (PTC), the less aggressive form of thyroid tumor, may progress to the more aggressive follicular thyroid carcinoma (FTC) and eventually to the anaplastic thyroid carcinoma (ATC), and that to such progression contributes the presence of an inflammatory/immune suppressive tumor microenvironment. In this study, we investigated whether papillary tumor cells (BCPAP) could be infected by human herpes virus-6A (HHV-6A), and if viral infection could induce effects related to cancer progression. We found that the virus dysregulated the expression of several microRNAs, such as miR-155, miR-9, and the miR-221/222 cluster, which are involved in different steps of carcinogenesis, and increased the secretion of pro-inflammatory cytokines, particularly IL-6, which may also sustain thyroid tumor cell growth and promote cancer progression. Genomic instability and the expression of PTEN, reported to act as an oncogene in mutp53-carrying cells such as BCPAP, also increased following HHV-6A-infection. These findings suggest that a ubiquitous herpesvirus such as HHV-6A, which displays a marked tropism for thyrocytes, could be involved in the progression of PTC towards more aggressive forms of thyroid tumor.

Acetylation increases expression, interaction with TRAPPC4 and surface localization of PD-L1

PD-L1 is an immune checkpoint inhibitor, whose surface expression may be exploited by cancer cells to escape T cell-mediated immune recognition. PD-L1 expression and nuclear localization can be affected by epigenetic modifications, such as acetylation. In this study, we showed that VPA, a class I/IIa HDAC inhibitor, upregulated PD-L1 expression on the surface of pancreatic cancer cells. To this effect contributed the increased transcription, in correlation with histone acetylation of the PD-L1 gene and the acetylation of PD-L1 protein, which led to an increased interaction with TRAPPC4, molecule involved in PD-L1 recycling to the cell membrane. Interestingly, the BRD4 inhibitor JQ-1, counteracted PD-L1 transcription and reduced its surface expression, suggesting that such a combination could improve the outcome of VPA treatment, also because it increased the cytotoxic effect of VPA. Also considering that this HDACi did not upregulate PD-L2 and that the supernatant of VPA-treated cancer cells did not increase PD-L1 expression on the surface of macrophages exposed to it.

NFE2L2 and STAT3 Converge on Common Targets to Promote Survival of Primary Lymphoma Cells

NFE2L2 and STAT3 are key pro-survival molecules, and thus, their targeting may represent a promising anti-cancer strategy. In this study, we found that a positive feedback loop occurred between them and provided evidence that their concomitant inhibition efficiently impaired the survival of PEL cells, a rare, aggressive B cell lymphoma associated with the gammaherpesvirus KSHV and often also EBV. At the molecular level, we found that NFE2L2 and STAT3 converged in the regulation of several pro-survival molecules and in the activation of processes essential for the adaption of lymphoma cells to stress. Among those, STAT3 and NFE2L2 promoted the activation of pathways such as MAPK3/1 and MTOR that positively regulate protein synthesis, sustained the antioxidant response, expression of molecules such as MYC, BIRC5, CCND1, and HSP, and allowed DDR execution. The findings of this study suggest that the concomitant inhibition of NFE2L2 and STAT3 may be considered a therapeutic option for the treatment of this lymphoma that poorly responds to chemotherapies.

mTORC1/ERK1/2 Interplay Regulates Protein Synthesis and Survival in Acute Myeloid Leukemia Cell Lines

mTOR is constitutively activated in acute myeloid leukemia (AML) cells, as indicated by the phosphorylation of its substrates, 4EBP1 and P70S6K. Here, we found that quercetin (Q) and rapamycin (Rap) inhibited P70S6K phosphorylation, partially dephosphorylated 4EBP1, and activated ERK1/2 in U937 and THP1, two leukemia cell lines. ERK1/2 inhibition by U0126 induced a stronger dephosphorylation of mTORC1 substrates and activated AKT. The concomitant inhibition of ERK1/2 and AKT further dephosphorylated 4EBP1 and further increased Q- or Rap-mediated cytotoxicity, compared to the single ERK1/2 or AKT inhibition in cells undergoing Q- or Rap-treatments. Moreover, quercetin or rapamycin reduced autophagy, particularly when used in combination with the ERK1/2 inhibitor, U0126. This effect was not dependent on TFEB localization in nuclei or cytoplasm or on the transcription of different autophagy genes, but did correlate with the reduction in protein translation due to a strong eIF2α-Ser51 phosphorylation. Thus, ERK1/2, by limiting 4EBP1 de-phosphorylation and eIF2α phosphorylation, behaves as a paladin of protein synthesis. Based on these findings, the combined inhibition of mTORC1, ERK1/2, and AKT should be considered in treatment of AML.

NRF2 and STAT3: friends or foes in carcinogenesis?

NRF2 is a transcription factor that plays a pivotal role in carcinogenesis, also through the interaction with several pro-survival pathways. NRF2 controls the transcription of detoxification enzymes and a variety of other molecules impinging in several key biological processes. This perspective will focus on the complex interplay of NRF2 with STAT3, another transcription factor often aberrantly activated in cancer and driving tumorigenesis as well as immune suppression. Both NRF2 and STAT3 can be regulated by ER stress/UPR activation and their cross-talk influences and is influenced by autophagy and cytokines, contributing to shape the microenvironment, and both control the execution of DDR, also by regulating the expression of HSPs. Given the importance of these transcription factors, more investigations aimed at better elucidating the outcome of their networking could help to discover new and more efficacious strategies to fight cancer.

JQ-1/bortezomib combination strongly impairs MM and PEL survival by inhibiting c-Myc and mTOR despite the activation of prosurvival mechanisms

Multiple myeloma (MM) and primary effusion lymphoma (PEL) are two aggressive hematologic cancers against which bortezomib and JQ-1, proteasome and bromodomain and extraterminal domain (BET) inhibitors, respectively, have been shown to have a certain success. However, the combination of both seems to be more promising than the single treatments against several cancers, including MM. Indeed, in the latter, proteasome inhibition upregulated nuclear respiratory factor 1 (NRF1), and such a prosurvival effect was counteracted by BET inhibitors. In the present study, we found that JQ-1/bortezomib induced a strong cytotoxic effect against PEL and discovered new insights into the cytotoxic mechanisms induced by such a drug combination in PEL and MM cells. In particular, a stronger c-Myc downregulation, leading to increased DNA damage, was observed in these cells after treatment with JQ-1/bortezomib than after treatment with the single drugs. Such an effect contributed to mechanistic target of rapamycin (mTOR)-phosphorylated eukaryotic translation initiation factor 4E-binding protein 1 (p-4EBP1) axis inhibition, also occurring through c-Myc downregulation. However, besides the prodeath effects, JQ-1/bortezomib activated unfolded protein response (UPR) and autophagy as prosurvival mechanisms. In conclusion, this study demonstrated that JQ-1/bortezomib combination could be a promising treatment for MM and PEL, unveiling new molecular mechanisms underlying its cytotoxic effect, and suggested that UPR and autophagy inhibition could be exploited to further potentiate the cytotoxicity of JQ-1/bortezomib.

c-Myc Sustains Pancreatic Cancer Cell Survival and mutp53 Stability through the Mevalonate Pathway

It has been shown that wild-type (wt)p53 inhibits oncogene c-Myc while mutant (mut)p53 may transactivate it, with an opposite behavior that frequently occurs in the crosstalk of wt or mutp53 with molecules/pathways promoting carcinogenesis. Even if it has been reported that mutp53 sustains c-Myc, whether c-Myc could in turn influence mutp53 expression remains to be investigated. In this study, we found that pharmacological or genetic inhibition of c-Myc downregulated mutp53, impaired cell survival and increased DNA damage in pancreatic cancer cells. At the molecular level, we observed that c-Myc inhibition reduced the expression of mevalonate kinase (MVK), a molecule belonging to the mevalonate pathway that—according to previous findings—can control mutp53 stability, and thus contributes to cancer cell survival. In conclusion, this study unveils another criminal alliance between oncogenes, such as c-Myc and mutp53, that plays a key role in oncogenesis.

ATF6 prevents DNA damage and cell death in colon cancer cells undergoing ER stress

Colon cancer represents one of the most common and aggressive cancers in its advanced state. Among the most innovative anti-cancer approaches, the manipulation of UPR is a promising one, effective also against cancers carrying dysfunctional p53. Interestingly, it is emerging that UPR cross-talks with DDR and that targeting the interplay between these two adaptive responses may be exploited to overcome the resistance to the single DDR- and UPR-targeting treatments. Previous studies have highlighted the role of IRE1 alpha and PERK UPR sensors on DDR, while the impact of ATF6 on this process remains under-investigated. This study shows for the first time that ATF6 sustains the expression level of BRCA-1 and protects colon cancer cells from the cytotoxic effect of ER stressors DPE and Thapsigargin. At molecular level, ATF6 activates mTOR to sustain the expression of HSP90, of which BRCA-1 is a client protein. Therefore, pharmacological or genetic inhibition of ATF6 promoted BRCA-1 degradation and increased DNA damage and cell death, particularly in combination with Adriamycin. All together this study suggests that targeting ATF6 may not only potentiate the cytotoxic effect of drugs triggering ER stress but may render colon cancer cells more sensitive to Adriamycin and possibly to other DNA damaging agents used to treat colon cancer.

VPA and TSA Interrupt the Interplay between mutp53 and HSP70, Leading to CHK1 and RAD51 Down-Regulation and Sensitizing Pancreatic Cancer Cells to AZD2461 PARP Inhibitor

HDAC inhibitors (HDACi) represent promising anti-cancer treatments, as the acetylation of histone and non-histone proteins is often dysregulated in cancer and contributes to cancer onset and progression. HDACi have been also reported to increase the cytotoxicity of DNA-damaging agents, such as radiation or cisplatin. In this study, we found that TSA and, even more effectively, VPA synergized with AZD2461, PARP1, 2 and 3 inhibitor (PARPi) to induce DNA damage and reduce pancreatic cancer cell survival. At a molecular level, VPA and TSA down-regulated CHK1 and RAD51, which is correlated with the interruption of the cross-talk between mutp53 and HSP70. Moreover, VPA and to a lesser extent TSA reactivated wtp53 in these cells, which contributed to CHK1 and RAD51 reduction. These findings suggest that the combination of HDACi and PARPi might improve the treatment of pancreatic cancer, which remains one of the most aggressive and therapy-resistant cancers.

p62/SQSTM1 promotes mitophagy and activates the NRF2-mediated anti-oxidant and anti-inflammatory response restraining EBV-driven B lymphocyte proliferation

Reactive oxygen species (ROS) and DNA repair respectively promote and limit oncogenic transformation of B cells driven by Epstein-Barr virus (EBV). We have previously shown that EBV infection reduced autophagy in primary B lymphocytes and enhanced ROS and interleukin 6 (IL-6) release, promoting B cell proliferation and immortalization. In this study, we explored the role of p62/SQSTM1, accumulated as a consequence of autophagy reduction in EBV-infected B lymphocytes, and found that it exerted a growth suppressive effect in these cells. At molecular level, we found that p62 counteracted IL-6 production and ROS increase by interacting with NRF2 and promoting mitophagy. Moreover, p62/NRF2 axis sustained the expression level of H2AX and ataxia-telangiectasia mutated (ATM), whose activation has been shown to have growth-suppressive effects during the first steps of EBV-infection, before latency is established. In conclusion, this study shows for the first time that the accumulation of p62 and the activation of p62/axis counteracted EBV-driven proliferation of primary B lymphocytes.

Anticancer effect of AZD2461 PARP inhibitor against colon cancer cells carrying wt or dysfunctional p53

Colon cancer is one of the most common cancers, currently treated with traditional chemotherapies or alternative therapies. However, these treatments are still not enough effective and induce several side effects, so that the search of new therapeutic strategies is needed. The use of Poly-(ADP-ribose)-polymerase (PARP) inhibitors, although originally approved against BRCA-1 or BRCA-2 mutated cancers, has been extended, particularly in combination with other treatments, to cure cancers that do not display defects in DNA repair signaling pathways. The role of p53 oncosuppressor in the regulating the outcome of PARP inhibitor treatment remains an open issue. In this study, we addressed this topic by using a well-tolerated PARP 1/2/3 inhibitor, namely AZD2461, against colon cancer cell lines with different p53 status. We found that AZD2461 reduced cell proliferation in wtp53 and p53-/- cancer cells by increasing ROS and DNA damage, while R273H mutant (mut) p53 counteracted these effects. Moreover, AZD2461 improved the reduction of cell proliferation by low dose radiation (IR) in wtp53 cancer cells, in which a down-regulation of BRCA-1 occurred. AZD2461 did not affect cell proliferation of mutp53 colon cancer cells also in combination with low dose radiation, suggesting that only wt p53 or p53 null colon cancer cells could benefit AZD2461 treatment.

DNA damage triggers an interplay between wtp53 and c-Myc affecting lymphoma cell proliferation and Kaposi sarcoma herpesvirus replication

The induction of DNA damage together with the interference with DNA repair represents a promising strategy in cancer treatment. Here we show that the PARP-1/2/3 inhibitor AZD2461 in combination with the CHK1 inhibitor UCN-01 altered the DNA damage response and reduced cell proliferation in PEL cells, an aggressive B cell lymphoma highly resistant to chemotherapies. AZD2461/UCN-01 combination activated p53/p21 and downregulated c-Myc in these cells, leading to a reduced expression level of RAD51, molecule involved in DNA repair. The effect of AZD2461/UCN-01 on c-Myc and p53/p21 was inter-dependent and, besides impairing cell proliferation, contributed to the activation of the replicative cycle of KSHV, carried in a latent state in PEL cells. Finally, we found that the pharmacological or genetic inhibition of p21 counteracted the viral lytic cycle activation and further reduced PEL cell proliferation, suggesting that it could induce a double beneficial effect in this setting. This study unveils that, therapeutic approaches, based on the induction of DNA damage and the reduction of DNA repair, could be used to successfully treat this malignant lymphoma.

Role of UPR Sensor Activation in Cell Death-Survival Decision of Colon Cancer Cells Stressed by DPE Treatment

Polyphenols have been shown to possess several beneficial properties, including properties involved in the prevention or treatment of cancer. Among these polyphenols, a leading role is played by dihydroxyphenylethanol (DPE), the most powerful antioxidant compound contained in the olive oil. DPE has been previously reported to induce endoplasmic reticulum (ER) stress and to reduce cell survival in colon cancer, one of the most common and aggressive cancers in developed countries. In this study, we further investigated the activation of UPR by DPE and explored the roles of the three UPR sensors, inositol-requiring enzyme (IRE) 1 alpha, protein kinase RNA-like endoplasmic reticulum kinase (PERK), and activating transcription factor (ATF6), in the cell death-survival decision of wt and mutp53 colon cancer cells and the underlying mechanisms involved. We also unveiled a new interplay between ATF6 and wt, as well as mutp53, which may have important implications in cancer therapy.

Lovastatin reduces PEL cell survival by phosphorylating ERK1/2 that blocks the autophagic flux and engages a cross-talk with p53 to activate p21

Statins are inhibitors of the mevalonate pathway that besides being cholesterol lowering agents, display anti‐cancer properties. This is because cholesterol is an essential component of cell membranes but also because the mevalonate pathway controls protein farnesylation and geranylation, processes essential for the activity of GTPase family proteins. In this study, we found that Lovastatin exerted a dose‐ and time‐dependent cytotoxic effect against PEL cells, an aggressive B cell lymphoma strictly associated with the gammaherpesvirus KSHV and characterized by a poor response to conventional chemotherapies. At molecular level, Lovastatin by dephosphorylating STAT3, induced ERK1/2 activation that inhibited autophagy and phosphorylated p53ser15 that in turn maintained ERK1/2 activated and up‐regulated p21. However, p21 played a pro‐survival role in this setting, as its inhibition by UC2288 further reduced cell survival in PEL cells undergoing Lovastatin treatment. In conclusion, this study suggests that Lovastatin may represent a valid therapeutic alternative against PEL cells, especially if used in combination with p21 inhibitors.

PGE2 Released by Pancreatic Cancer Cells Undergoing ER Stress Transfers the Stress to DCs Impairing Their Immune Function

This study shows that pancreatic cancer cells undergoing cell death by valproic acid (VPA) treatment activated dendritic cells (DCs) more efficiently than those treated with trichostatin A (TSA), as demonstrated by CD86 and CD80 surface expression. Surprisingly though, DCs cultured in the presence of supernatant derived from VPA-treated cancer cells showed a reduced allostimulatory capacity and an increased release of IL10 and IL8 cytokines in comparison with those exposed to TSA-treated cell culture supernatant. Searching for molecular mechanisms leading to such differences, we found that VPA treatment dysregulated choline metabolism and triggered a stronger endoplasmic reticulum (ER) stress in pancreatic cancer cells than TSA, upregulating CCAAT/enhancer-binding protein homologous protein, and activated cyclooxygenase-2, thus promoting the release of prostaglandin (PG) E2. Interestingly, dysfunctional DCs cultured in the presence of VPA-treated cells culture supernatant showed a higher level of intracellular reactive oxygen species, 4-hydroxy-trans-2-nonenal protein adducts, and ER stress, as evidenced by the upregulation of spliced X-box binding protein 1 (XBP1s), effects that were reduced when DCs were exposed to supernatant of cancer cells treated with Celecoxib before VPA. Celecoxib prevented PGE2 release, restoring the function of DCs exposed to VPA-treated cells culture supernatant, and a similar effect was obtained by silencing XBP1s in DCs treated with VPA-treated cells culture supernatant. These results suggest that PGE2 could be one of the yet unidentified factors able to transfer the stress from cancer cells to DCs, resulting in an impairment of their function.

p53-R273H Sustains ROS, Pro-Inflammatory Cytokine Release and mTOR Activation While Reducing Autophagy, Mitophagy and UCP2 Expression, Effects Prevented by wtp53

p53 is the most frequently mutated or inactivated gene in cancer, as its activity is not reconcilable with tumor onset and progression. Moreover, mutations in the p53 gene give rise to mutant proteins such as p53-R273H that, besides losing the wild type p53 (wtp53) capacity to safeguard genome integrity, may promote carcinogenesis, mainly due to its crosstalk with pro-oncogenic pathways. Interestingly, the activation of oncogenic pathways is interconnected with reactive oxygen species (ROS) and the release of pro-inflammatory cytokines that contribute to create an inflammatory/pro-tumorigenic milieu. In this study, based on experiments involving p53-R273H silencing and transfection, we showed that this mutant p53 (mutp53) promoted cancer cell survival by increasing intracellular ROS level and pro-inflammatory/immune suppressive cytokine release, activating mTOR, reducing autophagy and mitophagy and downregulating uncoupling protein 2 (UCP2). Interestingly, p53-R273H transfection into cancer cells carrying wtp53 induced none of these effects and resulted in p21 upregulation. This suggests that wtp53 may counteract several pro-tumorigenic activities of p53-R273H and this could explain the lower aggressiveness of cancers carrying heterozygous mutp53 in comparison to those harboring homozygous mutp53.

IRE1 Alpha/XBP1 Axis Sustains Primary Effusion Lymphoma Cell Survival by Promoting Cytokine Release and STAT3 Activation

Primary Effusion Lymphoma (PEL) is a highly aggressive B cell lymphoma associated with Kaposi's Sarcoma-associated Herpesvirus (KSHV). It is characterized by a high level of basal Endoplasmic Reticulum (ER) stress, Unfolded Protein Response (UPR) activation and constitutive phosphorylation of oncogenic pathways such as the Signal Transducer and activator of Transcription (STAT3). In this study, we found that the inositol requiring kinase (IRE) 1alpha/X-box binding protein (XBP1) axis of UPR plays a key role in the survival of PEL cells, while double stranded RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor (ATF) 6 slightly influence it, in correlation with the capacity of the IRE1alpha/XBP1 axis to induce the release of interleukin (IL)-6, IL-10 and Vascular-Endothelial Growth Factor (VEGF). Moreover, we found that IRE1alpha/XBP1 inhibition reduced STAT3 Tyr705 phosphorylation and induced a pro-survival autophagy in PEL cells. In conclusion, this study suggests that targeting the IRE1alpha/XBP1 axis represents a promising strategy against PEL cells and that the cytotoxic effect of this treatment may be potentiated by autophagy inhibition.

The cross-talk between STAT1/STAT3 and ROS up-regulates PD-L1 and promotes the release of pro-inflammatory/immune suppressive cytokines in primary monocytes infected by HHV-6B

Programmed death ligand 1 (PD-L1) up-regulation on antigen presenting cells induces T cell dysfunction, strongly impairing immune response. Human Herpesviruses (HHV) 6B is a β-herpesvirus that, although displays a higher tropism for T cells, can infect other immune cells including monocytes and dendritic cells (DCs) and neuronal cells. We have previously shown that HHV-6B infection of primary monocytes reduced autophagy and induced Endoplasmic Reticulum (ER) stress/ Unfolded Protein Response (UPR), impairing their survival and differentiation into DCs. In this study, we found that PD-L1 expression was up-regulated by HHV-6B on the surface of infected monocytes and that its extracellular release also increased, effects known to lead to an impairment of anti-viral immune response. At molecular level, PD-L1 up-regulation correlated with the activation of a positive regulatory circuit between the increase of intracellular ROS and the activation of STAT1 and STAT3 induced by HHV-6B, accompanied by a high release of pro-inflammatory/immune suppressive cytokines. In conclusion, this study unveils new strategies put in place by HHV-6B to induce immune dysfunction and the underlying molecular pathways that could be targeted to counteract such immune suppressive effects.

KSHV dysregulates bulk macroautophagy, mitophagy and UPR to promote endothelial to mesenchymal transition and CCL2 release, key events in viral-driven sarcomagenesis

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of KS, an aggressive neoplasm that mainly occurs in immune-compromised patients. Spindle cells represent the main feature of this aggressive malignancy and arise from KSHV-infected endothelial cells undergoing endothelial to mesenchymal transition (EndMT), which changes their cytoskeletal composition and organization. As in epithelial to mesenchymal transition (EMT), EndMT is driven by transcription factors such as SNAI1 and ZEB1 and implies a cellular reprogramming mechanism regulated by several molecular pathways, particularly PI3K/AKT/MTOR. Here we found that KSHV activated MTOR and its targets 4EBP1 and ULK1 and reduced bulk macroautophagy and mitophagy to promote EndMT, activate ER stress/unfolded protein response (UPR), and increase the release of the pro-angiogenic and pro-inflammatory chemokine CCL2 by HUVEC cells. Our study suggests that the manipulation of macroautophagy, mitophagy and UPR and the interplay between the three could be a promising strategy to counteract EndMT, angiogenesis and inflammation, the key events of KSHV-driven sarcomagenesis.

STAT3 and mutp53 Engage a Positive Feedback Loop Involving HSP90 and the Mevalonate Pathway

Oncosuppressor TP53 and oncogene STAT3 have been shown to engage an interplay in which they negatively influence each other. Conversely, mutant (mut) p53 may sustain STAT3 phosphorylation by displacing SH2 phosphatase while whether STAT3 could influence mutp53 has not been clarified yet. In this study we found that pharmacologic or genetic inhibition of STAT3 in both glioblastoma and pancreatic cancer cells, carrying mutp53 protein, reduced mutp53 expression level by down-regulating chaperone HSP90 as well as molecules belonging to the mevalonate pathway. On the other hand, HSP90 and the mevalonate pathway were involved in sustaining STAT3 phosphorylation mediated by mutp53. In conclusion, this study unveils for the first time that mutp53 can establish with STAT3, similarly to what observed with other oncogenic pathways, a criminal alliance with a crucial role in promoting cancerogenesis.

PBA Preferentially Impairs Cell Survival of Glioblastomas Carrying mutp53 by Reducing Its Expression Level, Stabilizing wtp53, Downregulating the Mevalonate Kinase and Dysregulating UPR

Phenylbutyrate (PBA) is a derivative of Butyric Acid (BA), which has the characteristics of being a histone deacetylase (HDAC) inhibitor and acting as a chemical chaperone. It has the potential to counteract a variety of different diseases, from neurodegeneration to cancer. In this study, we investigated the cytotoxic effect of PBA against glioblastoma cells carrying wt or mutant (mut) p53 and found that it exerted a higher cytotoxic effect against the latter in comparison with the former. This could be due to the downregulation of mutp53, to whose pro-survival effects cancer cells become addicted. In correlation with mutp53 reduction and wtp53 activation, PBA downregulated the expression level of mevalonate kinase (MVK), a key kinase of the mevalonate pathway strongly involved in cancer cell survival. Here we differentiated the chaperoning function of PBA from the others anti-cancer potentiality by comparing its effects to those exerted by NaB, another HDACi that derives from BA but, lacking the phenyl group, cannot act as a chemical chaperone. Interestingly, we observed that PBA induced a stronger cytotoxic effect compared to NaB against U373 cells as it skewed the Unfolded Protein Response (UPR) towards cell death induction, upregulating CHOP and downregulating BIP, and was more efficient in downregulating MVK. The findings of this study suggest that PBA represents a promising molecule against glioblastomas, especially those carrying mutp53, and its use, approved by FDA for urea cycle disorders, should be extended to the glioblastoma anticancer therapy.

HHV-6A infection dysregulates autophagy/UPR interplay increasing beta amyloid production and tau phosphorylation in astrocytoma cells as well as in primary neurons, possible molecular mechanisms linking viral infection to Alzheimer's disease

HHV-6A and HHV-6B are neurotropic viruses able to dysregulate autophagy and activate ER stress/UPR in several cell types. The appropriate functioning of these processes is required for cell homeostasis, particularly in post-mitotic cells such as neuronal cells. Interestingly, neurodegenerative diseases such as Alzheimer's disease (AD) are often accompanied by autophagy dysregulation and abnormal UPR activation. This study demonstrated for the first time that HHV-6A infection of astrocytoma cells and primary neurons reduces autophagy, increases Aβ production and activates ER stress/UPR promoting tau protein hyper-phosphorylation. Our results support previous studies suggesting that HHV-6A infection may play a role in AD and unveil the possible underlying molecular mechanisms involved.

Quercetin Interrupts the Positive Feedback Loop Between STAT3 and IL-6, Promotes Autophagy, and Reduces ROS, Preventing EBV-Driven B Cell Immortalization

The oncogenic gammaherpesvirus Epstein–Barr virus (EBV) immortalizes in vitro B lymphocytes into lymphoblastoid cell lines (LCLs), a model that gives the opportunity to explore the molecular mechanisms driving viral tumorigenesis. In this study, we addressed the potential of quercetin, a widely distributed flavonoid displaying antioxidant, anti-inflammatory, and anti-cancer properties, in preventing EBV-driven B cell immortalization. The results obtained indicated that quercetin inhibited thectivation of signal transducer and activator of transcription 3 (STAT3) induced by EBV infection and reduced molecules such as interleukin-6 (IL-6) and reactive oxidative species (ROS) known to be essential for the immortalization process. Moreover, we found that quercetin promoted autophagy and counteracted the accumulation of sequestosome1/p62 (SQSTM1/p62), ultimately leading to the prevention of B cell immortalization. These findings suggest that quercetin may have the potential to be used to counteract EBV-driven lymphomagenesis, especially if its stability is improved.

Mutant p53, Stabilized by Its Interplay with HSP90, Activates a Positive Feed-Back Loop Between NRF2 and p62 that Induces Chemo-Resistance to Apigenin in Pancreatic Cancer Cells

Pancreatic cancer is one of the most aggressive cancers whose prognosis is worsened by the poor response to the current chemotherapies. In this study, we investigated the cytotoxic effect of Apigenin, against two pancreatic cell lines, namely Panc1 and PaCa44, harboring different p53 mutations. Apigenin is a flavonoid widely distributed in nature that displays anti-inflammatory and anticancer properties against a variety of cancers. Here we observed that Apigenin exerted a stronger cytotoxic effect against Panc1 cell line in comparison to PaCa44. Searching for mechanisms responsible for such different effect, we found that the higher cytotoxicity of Apigenin correlated with induction of higher level of intracellular ROS, reduction of mutant (mut) p53 and HSP90 expression and mTORC1 inhibition. Interestingly, we found that mutp53 was stabilized by its interplay with HSP90 and activates a positive feed-back loop between NRF2 and p62, up-regulating the antioxidant response and reducing the cytotoxicity of Apigenin. These results suggest that targeting the molecules involved in the mTOR-HSP90-mutp53-p62-NRF2-antioxidant response axis could help to overcome the chemo-resistance of pancreatic cancer to Apigenin.

STAT3 phosphorylation affects p53/p21 axis and KSHV lytic cycle activation

The Tyr705 STAT3 constitutive activation, besides promoting PEL cell survival, contributes to the maintenance of viral latency. We found indeed that its de-phosphorylation by AG490 induced KSHV lytic cycle. Moreover, Tyr705 STAT3 de-phosphorylation, mediated by the activation of tyrosine phosphatases, together with the increase of Ser727 STAT3 phosphorylation contributed to KSHV lytic cycle induction by TPA. We then observed that p53-p21 axis, essential for the induction of KSHV replication, was activated by the inhibition of Tyr705 and by the increase of Ser727 STAT3 phosphorylation. As a possible link between STAT3, p53-p21 and KSHV lytic cycle, we found that TPA and AG490 reduced the expression of KAP-1, promoting p53 stability, p21 transcription and KSHV lytic cycle activation in PEL cells.

Could autophagy dysregulation link neurotropic viruses to Alzheimer's disease?

Neurotropic herpesviruses have been associated with the onset and progression of Alzheimer’s disease, a common form of dementia that afflicts a large percentage of elderly individuals. Interestingly, among the neurotropic herpesviruses, herpes simplex virus-1, human herpesvirus-6A, and human herpesvirus-6B have been reported to infect several cell types present in the central nervous system and to dysregulate autophagy, a process required for homeostasis of cells, especially neurons. Indeed autophagosome accumulation, indicating an unbalance between autophagosome formation and autophagosome degradation, has been observed in neurons of Alzheimer’s disease patients and may play a role in the intracellular and extracellular accumulation of amyloid β and in the altered protein tau metabolism. Moreover, herpesvirus infection of central nervous system cells such as glia and microglia can increase the production of oxidant species through the alteration of mitochondrial dynamics and promote inflammation, another hallmark of Alzheimer’s disease. This evidence suggests that it is worth further investigating the role of neurotropic herpesviruses, particularly human herpesvirus-6A/B, in the etiopathogenesis of Alzheimer’s disease.

Impact of HHV-6A and HHV-6B lytic infection on autophagy and endoplasmic reticulum stress

Herpesviruses are known to manipulate autophagy to optimize their replication, counteract immune response and probably to promote tumourigenesis. This study explored, for the first time, the impact of human herpesvirus (HHV)-6 lytic infection on autophagy and demonstrated that HHV-6A and B (viruses sharing more than 80 % homology) differently affected this cellular process. Indeed, while HHV-6A (GS) infection of HSB2 cells promoted autophagy, HHV-6B (Z29) or the virus isolated from the serum of roseola infantum-affected patient-inhibited autophagy in Molt-3 cells or in PBMCs, respectively. Interestingly, the different behaviour of HHV-6A and B on the autophagic process was accompanied by different effects on endoplasmic reticulum stress, unfolded protein response and cell survival that was more strongly reduced by HHV-6B infection. We hypothesize that the ability to inhibit autophagy displayed by HHV-6B could be due to the fact that it contains gene homologues of those encoding for TRS1; the protein responsible for the block of autophagy by human cytomegalovirus. Understanding how HHV-6A/B infection regulates autophagy could be of particular interest, as it has been recently shown that this virus may be involved in Alzheimer's disease in which a dysregulation of autophagy may also play a role.

Metformin triggers apoptosis in PEL cells and alters bortezomib-induced Unfolded Protein Response increasing its cytotoxicity and inhibiting KSHV lytic cycle activation

Metformin, the most used drug for the treatment of diabetes type 2 patients, has been shown to have anti-cancer properties. In this study, we found that metformin induced apoptosis in Primary Effusion Lymphoma (PEL) cells, an aggressive B cell lymphoma associated with KSHV against which the conventional therapies usually fail. The cytotoxic effect of metformin correlated with intracellular reactive oxygen species reduction, activation of AMPK, the inhibition of pro-survival pathways such as mTOR and STAT3 and the down-regulation of v-FLIP, a latent viral antigen that also plays a pivotal role in PEL cell survival. Interestingly, we found that metformin could be used to potentiate the bortezomib-mediated cytotoxicity against PEL cells and to inhibit the activation of KSHV lytic cycle, a side effect of this treatment that resulted in a block of autophagy in these cells. Mechanistically, metformin altered UPR activated by bortezomib, leading to a reduced expression of BiP, up-regulation of CHOP and down-regulation of Bcl-2. In summary, this study suggests that metformin could represent a promising strategy for the treatment of PEL alone or in combination with bortezomib. In the latter case, besides exerting a stronger cytotoxic effect, it might be used to restrain bortezomib-induced viral replication that is involved in the maintenance and progression of KSHV-associated malignancies.

Concomitant reduction of c-Myc expression and PI3K/AKT/mTOR signaling by quercetin induces a strong cytotoxic effect against Burkitt's lymphoma

Burkitt's lymphoma is an aggressive B cell lymphoma whose pathogenesis involves mainly c-Myc translocation and hyperexpression, in addition to antigen-independent BCR signaling and, in some cases, EBV infection. As result of BCR signaling activation, the PI3K/AKT/mTOR pathway results constitutively activated also in the absence of EBV, promoting cell survival and counterbalancing the pro-apoptotic function that c-Myc may also exert. In this study we found that quercetin, a bioflavonoid widely distributed in plant kingdom, reduced c-Myc expression and inhibited the PI3K/AKT/mTOR activity in BL, leading to an apoptotic cell death. We observed a higher cytotoxic effect against the EBV-negative BL cells in comparison with the positive ones, suggesting that this oncogenic gammaherpesvirus confers an additional resistance to the quercetin treatment. Besides cell survival, PI3K/AKT/mTOR pathway also regulates autophagy: we found that quercetin induced a complete autophagic flux in BL cells, that contributes to c-Myc reduction in some of these cells. Indeed, autophagy inhibition by chloroquine partially restored c-Myc expression in EBV-positive (Akata) and EBV-negative (2A8) cells that harbor c-Myc mutation. Interestingly, chloroquine did not affect the quercetin-mediated reduction of c-Myc expression in Ramos cells, that have no c-Myc mutation in the coding region, although autophagy was induced. These results suggest that mutant c-Myc could be partially degraded through autophagy in BL cells, as previously reported for other mutant oncogenic proteins.

Spread of a carbapenem- and colistin-resistant Acinetobacter baumannii ST2 clonal strain causing outbreaks in two Sicilian hospitals

BACKGROUND

Infections caused by multidrug-resistant (MDR) Acinetobacter baumannii have become an important healthcare-associated problem, particularly in intensive care units (ICUs).

AIM

To investigate the emergence of carbapenem- and colistin-resistant A. baumannii infections in two Sicilian hospitals.

METHODS

From October 2008 to May 2011, a period which included two Italian Nosocomial Infections Surveillance in ICUs network (SPIN-UTI) project surveys, all carbapenem-resistant A. baumannii isolates from the ICUs of two hospitals in Catania, Italy, were prospectively collected. Minimum inhibitory concentrations (MICs) were measured by agar dilution, and phenotypic testing for metallo-β-lactamase (MBL) production was performed. Carbapenem resistance genes and their genetic elements were identified by polymerase chain reaction and sequencing. Genotypic relatedness was assessed by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing. Patient-based surveillance was conducted using the SPIN-UTI protocol and previous antibiotic consumption was recorded.

FINDINGS

Twenty-six carbapenem-resistant A. baumannii were identified. Imipenem and meropenem MICs ranged from 4 to >32 mg/L, and 15 isolates exhibited high-level colistin resistance (MICs >32 mg/L). PFGE demonstrated that all isolates belonged to a unique clonal type and were assigned to ST2 of the international clone II. They harboured an intrinsic blaOxA-51-like carbapenemase gene, blaOxA-82, which was flanked upstream by ISAba1.

CONCLUSIONS

The dissemination of clonally related isolates of carbapenem-resistant A. baumannii in two hospitals is described. Simultaneous resistance to colistin in more than half of the isolates is a problem for effective antibiotic treatment. Prior carbapenem and colistin consumption may have acted as triggering factors.

Survival and Complications in Thalassemia

The life expectancy of patients with thalassemia major has significantly increased in recent years, as reported by several groups in different countries. However, complications are still frequent and affect the patients' quality of life. In a recent study from the United Kingdom, it was found that 50% of the patients had died before age 35. At that age, 65% of the patients from an Italian long-term study were still alive. Heart disease is responsible for more than half of the deaths. The prevalence of complications in Italian patients born after 1970 includes heart failure in 7%, hypogonadism in 55%, hypothyroidism in 11%, and diabetes in 6%. Similar data were reported in patients from the United States. In the Italian study, lower ferritin levels were associated with a lower probability of experiencing heart failure and with prolonged survival. Osteoporosis and osteopenia are common and affect virtually all patients. Hepatitis C virus antibodies are present in 85% of multitransfused Italian patients, 23% of patients in the United Kingdom, 35% in the United States, 34% in France, and 21% in India. Hepatocellular carcinoma can complicate the course of hepatitis. A survey of Italian centers has identified 23 such cases in patients with a thalassemia syndrome. In conclusion, rates of survival and complication-free survival continue to improve, due to better treatment strategies. New complications are appearing in long-term survivors. Iron overload of the heart remains the main cause of morbidity and mortality.

Antibodies against ox-LDL serum levels in patients with hepatocellular carcinoma

AIM

Hepatocellular carcinoma (HCC) is a malignancy with high incidence worldwide. The related cachexia is induced by proinflammatory cytokines, responsible for a wide number of metabolic disorders, essentially including lipidic and oxidative metabolism. Oxidized LDL (ox-LDL), produced by LDL-cholesterol oxidation, are one of the risk factors for atheromatosis. Also, ox-LDL act on the deliverance of some cytokines involved in the development and progression of a lot of human tumours. The removal of ox-LDL from the blood is performed by the liver. The intracellular amount of ox-LDL, through various cytokines, might induce HCC by reduction of the apoptotic mechanism of protection. Our aim was to evaluate the behaviour of serum antibodies against ox-LDL levels in order to study their possible changes and influences on a study series composed of HCC patients.

METHODS

We enrolled 41 patients (29 males, mean age 67.45+/-8.28 years and 12 females, mean age 64.62+/-7.2 years) with primitive HCC and 30 healthy control subjects (15 males and 15 females, mean age 61.86+/-2.51 years). Diagnosis of HCC was performed on the basis of clinical, laboratory and instrumental findings (Ultrasonography, Computed Tomography and Magnetic Nuclear Resonance, liver biopsy). Of the 41 HCC patients, 30 were affected by hepatitis C virus (HCV), 5 were HBsAg and HBcAg positive and 6 virus B and C negative but consumers of more than 150 g/day of alcohol. Liver biopsy confirmed the presence of HCC derived from cirrhosis in 10 of HCV positive patients, as well as in the patients with high alcohol consumption. Serum IgG antibodies versus the ox-LDL levels have been evaluated by ELISA method and oLAB reactive by Biomedica-Austria. Data have been analysed by 2 tailed Student's "t" test and a value of p<0.05 was considered significant.

RESULTS

Lipid pattern values were within the normal ranges except for the Lp(a), that presented low serum levels in both groups. Twenty-five patients presented HCC as well as severe chronic active hepatitis. Serum mean levels of ox-LDL antibodies (ox-LDL Ab), still being within the normal ranges, were significantly lower than in control subjects (p<0.001) in both sexes.

CONCLUSION

We hypothesize that the lower ox-LDL Ab serum levels in our HCC patients may be related to the smaller feeding of HCC patients or to the greater uptake of these modified lipoproteins by the hepatic reticular endothelial system. This phenomenon might result especially in the release of cytokines and growth factors for hepatocytes that may induce HCC development and progression.

Thromboembolic events in beta thalassemia major: an Italian multicenter study

Thromboembolic (TE) events have been frequently reported in beta-thalassemic patients in association with known risk factors such as diabetes, complex cardiopulmonary abnormalities, hypothyroidism, liver function anomalies, and postsplenectomy thrombocytosis. In a recent survey involving 9 Italian thalassemic centers, we identified 32 patients with TE episodes in a total of 735 subjects, of whom 683 had thalassemia major and 52 thalassemia intermedia, corresponding to 3.95 and 9.61%, respectively. There was a great variation in localization: the main one (16/32) was CNS, with a clinical picture of headache, seizures and hemiparesis. Other localizations were the pulmonary (3 patients), mesenteric (1 patient) and portal (2 patients) sites. There were 6 cases of deep venous thrombosis (2 in the upper limbs, 4 in the lower ones). Intracardiac thrombosis was found in 2 subjects and clinical and laboratory signs of DIC were observed in 2 others during pregnancy. Since our patients with TE events present a statistically significantly higher incidence of associated dysfunction (cardiomyopathy, diabetes, liver function anomalies, hypothyroidism) than those without TE events (50 vs. 13.8%), we suggest close monitoring of those patients who are at higher risk of developing TE events because of the presence of one or more of these predisposing factors.

Distribution and antibiotic resistance of isolates from lower respiratory tract and blood cultures from patients in three Italian intensive care units: a 2-year comparison

The distribution and antibiotic resistance of major pathogens isolated from patients in ICUs were studied by three Italian microbiological laboratories. Consecutive aerobic strains were collected over two different time periods from protected brushing bronchoscopy, broncho-alveolar lavage and blood cultures. A total of 420 strains were isolated during the first period (47.3% gram-negative and 52.7% gram-positive) and 412 over the second period (50.5% gram-negative and 49.5% gram-positive). Pseudomonas aeruginosa was the most frequently isolated organism from the respiratory tract followed by Staphylococcus aureus. Methicillin resistance was 47.9 and 44.5% in S. aureus and 63.0 and 65.1% in coagulase-negative staphylococci over the two periods. No glycopeptide-resistance was found in gram-positive organisms. Ceftazidime-resistance in Klebsiella pneumoniae was very high.

Plasma chitotriosidase activity in patients with beta-thalassemia

Chitotriosidase, a macrophage marker, which is extremely increased in plasma of Gaucher patients, was measured in patients with beta-thalassemia, an haematological disorder characterized by the genetic defect of beta-globin chains synthesis resulting in unproductive erythropoiesis and enormous expansion of the reticuloendothelial system. Plasma chitotriosidase was increased to a variable extent in 13 of 70 patients with beta-thalassemia major treated with the intense transfusion regimen and iron chelation therapy. It was normal in 22 and slightly elevated in 3 subjects with beta-thalassemia intermedia which were not transfused. The highest levels of plasma chitotriosidase, as high as in Gaucher patients, were found in 7 (10%) of the beta-thalassemia major patients which also had the highest degree of iron overload as judged by their serum ferritin level (> 3000 ng/ml), high SGPT level and elevated urinary iron excretion. To our knowledge, beta-thalassemia is hitherto the only disorder in which an increase of plasma chitotriosidase, comparable to that seen in Gaucher disease, may occur. The increase of plasma chitotriosidase activity in beta-thalassemia patients with high iron overload, could be related to an iron mediated damage to the lysosomal apparatus. In addition, similarly to Gaucher disease, the increased chitotriosidase production in beta-thalassemia might reflect macrophage activation probably related to the intracellular iron overload, storage of erythrocytes membrane break-down products and oxidation of excess alpha-hemoglobin subunits. Further studies are required to define the role of chitotriosidase evaluation to assess the efficacy of chelation therapy in reducing the macrophage activation due to intracellular iron overload in beta-thalassemia.

Focal neurological deficits in children with beta-thalassemia major

The hematologic disorder beta-thalassemia major is relatively common in Southern Italy. Stroke is a well described, though infrequently reported, complication of this disorder. We now report our experience regarding 300 children with beta-thalassemia major examined at the University of Catania, Italy, over a 20-year period. We encountered 9 patients (3%; 3 males, 6 females) with beta-thalassemia major who had hemorrhagic stroke. Two groups of patients can be identified: group 1 (2 patients 22%) with early-onset post-transfusion hemorrhage and group 2 (7 patients 77%) with delayed post-transfusion hemorrhage. In the first group, the hemorrhage occurred within 48 hours following blood transfusion. In the second group, hemorrhage occurred 7-15 days from last transfusion. In 5 patients out of 7 of this second group the first transfusion and ictal event both occurred after age five, suggesting prolonged chronic anemia might play a role in the hemorrhage.

Survey of sickle cell disease in Italy

BACKGROUND AND OBJECTIVE

The present study was designed to determine the distribution and severity of sickle cell disease (SCD) in Italy.

DESIGN AND METHODS

A questionnaire, requesting information about the cases of sickle cell disease that had been seen during previous years, was sent to all Italian centers of Pediatrics and Hematology. The questionnaire was simple and required personal, hematologic and clinical information.

RESULTS

A total of 696 cases were reported. The distribution of registered patients shows that, although the S gene originated mostly in Sicily and Southern Italy, 20% of patients with SCD now live in Central and Northern Italy. The types of SCD reported were as follows: compound heterozygotes HbS-beta thalassemia, (S-Th, 518 cases); homozygotes for HbS, (S-S, 149 cases); compound heterozygotes HbS and another abnormal hemoglobin (21 cases). The population of patients with SCD is younger than the general Italian population. More than 90% of patients have had no crises or only a limited number, namely, up to 6/year. Infections ranged between 0 and 6/year. Splenomegaly was reported in 28% and 80% of adult patients with S-S and S-Th, respectively. The prevalence of gallstones was 48%.

INTERPRETATION AND CONCLUSIONS

The survey established that 1) sickle cell disease is widely distributed in Italy; 2) while the clinical spectrum is extremely variable, severe forms are infrequent.

Clinical and biochemical reactivation of HBV infection in a thalassemic patient after bone marrow transplantation

The case of a young man affected by homozygous beta-thalassemia is reported who had serologic findings of a prior HBV infection and who presented with clinical and biochemical acute HBV infection probably caused by HBV reactivation after allogeneic bone marrow transplantation. The patient's clinical history suggests that HBV can persist without serological findings of HBsAg and HBV-DNA in persons previously infected by HBV and that HBV reactivation can occur 2 years after allogeneic bone marrow transplantation, as a result of immunosuppressive therapy or an HCV activation.

Alpha-interferon treatment of chronic hepatitis C after bone marrow transplantation for homozygous beta-thalassemia

No experience has been reported to date in treating chronic hepatitis C virus (HCV) infection with interferon (IFN) therapy after BMT, mainly due to concerns related to the impact of an immunomodulatory drug in patients who are immunologic and haematologic chimeras. However, chronic inflammatory activity related to HCV infection results in a chronic fibrogenous mechanism potentially leading to liver cirrhosis and hepatocellular carcinoma. Moreover, patients transplanted for beta-thalassemia could be at greater risk because of concomitant iron overload and pre-existing fibrous liver damage. Eleven patients with serological, biochemical, histological and molecular biological evidence of HCV infection were included in the study and treated for 6-12 months with recombinant IFN 24-65 months following BMT. The serum alanine aminotransferase (ALT) was persistently elevated (range 85-1242 U/l; mean 416) for at least 1 year prior to IFN treatment. Ten patients completed the protocol; five were considered as responders to treatment. In these five patients the liver histology showed an overall reduction of inflammation and necrosis: histological inflammatory activity improved from chronic active hepatitis (CAH) to chronic persistent hepatitis (three patients) or minimal residual inflammatory activity (two patients). The Knodell total activity score varied from 5.4 (range 3-9) to 1.4 (range 1-2; P = 0.05). All responding patients revealed negativization of serum HCV-RNA, that has been persistent in four (follow-up 1-3 years). ALT level fell to 15-80 U/l (mean 52; P = 0.0027). No major complications occurred during the therapy and no influence on marrow engraftment parameters were noted. We conclude that IFN therapy does not adversely interfere with engraftment and that it is a feasible therapy for treatment of chronic hepatitis C virus after BMT.

Persistence of Mediterranean anaemia in Sicily

We report 40 cases of homozygous beta thalassaemia, aged between 3 and 24 months, who were observed between January 1990 and June 1996 at the Thalassaemia Centre, Paediatric Department, Catania University. A questionnaire was used to find out the parents' knowledge of their risk before the birth of the affected children and showed that the persistence of Mediterranean anaemia in Sicily was mainly because of the following reasons: (1) poor information (62.5%), (2) laboratory error (12.5%), (3) difficulty in the differential diagnosis of beta thalassaemia trait (10%), and (4) not performing prenatal testing or selective abortion of an affected fetus (15%). We conclude that improved preventive measures at various medical and social levels can remove risk factors and so further reduce the incidence of Mediterranean anaemia in Sicily.

An alternative to continuous subcutaneous infusion of desferrioxamine in thalassaemic patients

Sixteen patients with thalassaemia major were treated with subcutaneous desferrioxamine (DF) 50 mg/kg/d, 5 consecutive days a week, for 8 weeks. Every other week the total dose was administered by 12 h infusion pump or by rapid injection of the same dose (25 x 2 mg/kg) twice a day. The two methods of DF administration produced no significant differences in urinary iron excretion. No significant changes in serum ferritin levels were observed at the end of the study. Compared with continuous infusion, rapid injection is equally efficacious, does not induce serious side-effects, is better accepted by the patients, and can improve their compliance to the iron-chelating therapy.

Evaluation of Taxol cytotoxicity on B-CLL cells in vitro

Taxol is a new antimicrotubule agent that, besides a well known efficacy against solid tumors, has shown activity in non-Hodgkin's lymphomas too. We therefore investigated its in vitro cytotoxic activity against cells from patients affected by chronic lymphocytic leukemia (CLL). Peripheral blood lymphocytes from 46 CLL patients were incubated for four days with Taxol at doses ranging from 0.01 to 10 mM and the cytotoxicity was evaluated by a colorimetric method (XTT). In most samples Taxol was inactive and the IC50 was > 10 mM in 40 out of 46 patients. It is worthwhile noting that four of the six in vitro responsive patients had unfavourable clinical features. In three unresponsive patients we also observed that Taxol was not able to induce apoptosis in vitro. In conclusion, based on in vitro data, it seems that Taxol is not an active drug in standard CLL but we cannot exclude some efficacy in other more rapidly proliferating lymphoproliferative disorders.

Elevation of interleukin 6 levels in patients with chronic hepatitis due to hepatitis C virus

Interleukin 6 (IL-6) is a pleiotropic cytokine produced by a wide variety of lymphoid and non-lymphoid tissues. We studied the relationship between IL-6 and the liver in an attempt to elucidate this cytokine's role in hepatitis C-induced liver inflammation. We investigated the behavior of serum IL-6 in 25 patients with chronic hepatitis C (divided into three groups depending on severity) and in 27 healthy controls. Our results showed a significant elevation (P < 0.0001) in serum IL-6 levels in the patients with chronic hepatitis C, correlated with the histological activity index (HAI) and their HCV-RNA serum levels. This rise may represent the expression of the hepatitis C virus-induced inflammatory state.

Immune status and the immune response to hepatitis B virus vaccine in thalassemic patients after allogeneic bone marrow transplantation

We evaluated the immune status with respect to HBV and the immune response to readministration of HBV vaccine in a series of 20 patients with homozygous beta-thalassemia, aged 6-23 years (mean age: 13.0 +/- 4.2) who had undergone allogeneic bone marrow transplantation (BMT). Thirteen of them (group A), had received three doses of plasma-derived HBV vaccine from 7 to 5 years before BMT and 4-5 weeks after the last dose of vaccine, they had had high serum levels of HBV antibodies (anti-HBs). The remaining seven patients (group B) had had clinical symptoms and laboratory evidence of HBV infection in childhood with markedly elevated serum of anti-HBs. Before revaccination, a significantly lower percentage of patients (P < 0.005) with seropositive levels of anti-HBs was observed in group A than in group B. After administration of the second dose of HBV vaccine the percentage of subjects with protective levels of anti-HBs rose to 100% in both groups of patients even if the geometric mean of titers of anti-HBs increased more significantly in group B patients than in group A. We conclude that the serum levels of anti-HBs afforded by HBV vaccine administered from 7 to 5 years previously are very low and probably non-protective in most beta-thalassemic patients after allogeneic BMT, and that at least two doses of HBV vaccine should be readministered from 18 to 24 months after BMT to achieve adequate and long-term protection from HBV.