Mycoviruses infecting Colletotrichum spp: A comprehensive review / Micoviroses em Colletotrichum spp: uma revisão abrangente

Abstract Colletotrichum is one of the most economically important fungal genera, which affects a wide range of hosts, specifically tropical and subtropical crops. Thus far, there have been several records of mycovirus infection in Colletotrichum spp., primarily by viruses of the Partitiviridae family. There have also been records of infections by mycoviruses of the Chrysoviridae family. Mycoviruses are (+)ssRNA and dsRNA genome viruses, which may or may not be enveloped. To date, no mycovirus with a DNA genome has been isolated from Colletotrichum spp. Typically, mycoviruses cause latent infections, although hypo- and hypervirulence have also been reported in Colletotrichum spp. In addition to its effects on pathogenic behavior, mycovirus infection can lead to important physiological changes, such as altered morphological characteristics, reduced vegetative growth, and suppressed conidia production. Therefore, research on mycoviruses infecting phytopathogenic fungi can help develop alternative methods to chemical control, which can cause irreversible damage to humans and the environment. From an agricultural perspective, mycoviruses can contribute to sustainable agriculture as biological control agents via changes in fungal physiology, ultimately resulting in the total loss of or reduction in the virulence of these pathogens.

Resumo Colletotrichum é um dos gêneros fúngicos mais importantes economicamente, afetando uma ampla gama de hospedeiros, especialmente em cultivos tropicais e subtropicais. Atualmente já existem diversos registros de infecção por micovírus em Colletotrichum spp., sendo a maioria dos já identificados classificados na família Partitiviridae. Ocorrem registros também de micovírus pertencentes à família Chrysoviridae. Compreendem vírus de genoma de (+)ssRNA e dsRNA que podem ser ou não envelopados. Ainda não foram identificados micovírus com genoma de DNA isolados de Colletotrichum. A infecção por micovírus pode ocorrer de forma latente, mas já foi observado em Colletotrichum spp. o fenômeno de hipo e hipervirulência. Além de influenciar no comportamento patogênico, a infecção pode causar mudanças fisiológicas importantes como alterações das características morfológicas, redução do crescimento vegetativo e redução na produção de conídios. O estudo com micovírus em fungos fitopatogênicos traz uma alternativa ao controle químico que é um método capaz de causar danos irreversíveis ao homem e o meio ambiente. Sob a perspectiva agrícola, os micovírus podem contribuir para agricultura sustentável como agentes de controle biológico. Isso porque obsevam-se mudanças importantes na fisiologia fúngica resultando na perda total ou redução da virulência desses patógenos.

Mycoviruses infecting Colletotrichum spp: a comprehensive review / Micoviroses em Colletotrichum spp: uma revisão abrangente

Colletotrichum is one of the most economically important fungal genera, which affects a wide range of hosts, specifically tropical and subtropical crops. Thus far, there have been several records of mycovirus infection in Colletotrichum spp., primarily by viruses of the Partitiviridae family. There have also been records of infections by mycoviruses of the Chrysoviridae family. Mycoviruses are (+)ssRNA and dsRNA genome viruses, which may or may not be enveloped. To date, no mycovirus with a DNA genome has been isolated from Colletotrichum spp. Typically, mycoviruses cause latent infections, although hypo- and hypervirulence have also been reported in Colletotrichum spp. In addition to its effects on pathogenic behavior, mycovirus infection can lead to important physiological changes, such as altered morphological characteristics, reduced vegetative growth, and suppressed conidia production. Therefore, research on mycoviruses infecting phytopathogenic fungi can help develop alternative methods to chemical control, which can cause irreversible damage to humans and the environment. From an agricultural perspective, mycoviruses can contribute to sustainable agriculture as biological control agents via changes in fungal physiology, ultimately resulting in the total loss of or reduction in the virulence of these pathogens.

Colletotrichum é um dos gêneros fúngicos mais importantes economicamente, afetando uma ampla gama de hospedeiros, especialmente em cultivos tropicais e subtropicais. Atualmente já existem diversos registros de infecção por micovírus em Colletotrichum spp., sendo a maioria dos já identificados classificados na família Partitiviridae. Ocorrem registros também de micovírus pertencentes à família Chrysoviridae. Compreendem vírus de genoma de (+)ssRNA e dsRNA que podem ser ou não envelopados. Ainda não foram identificados micovírus com genoma de DNA isolados de Colletotrichum. A infecção por micovírus pode ocorrer de forma latente, mas já foi observado em Colletotrichum spp. o fenômeno de hipo e hipervirulência. Além de influenciar no comportamento patogênico, a infecção pode causar mudanças fisiológicas importantes como alterações das características morfológicas, redução do crescimento vegetativo e redução na produção de conídios. O estudo com micovírus em fungos fitopatogênicos traz uma alternativa ao controle químico que é um método capaz de causar danos irreversíveis ao homem e o meio ambiente. Sob a perspectiva agrícola, os micovírus podem contribuir para agricultura sustentável como agentes de controle biológico. Isso porque obsevam-se mudanças importantes na fisiologia fúngica resultando na perda total ou redução da virulência desses patógenos.

Mycoviruses infecting Colletotrichum spp.: A comprehensive review

Abstract Colletotrichum is one of the most economically important fungal genera, which affects a wide range of hosts, specifically tropical and subtropical crops. Thus far, there have been several records of mycovirus infection in Colletotrichum spp., primarily by viruses of the Partitiviridae family. There have also been records of infections by mycoviruses of the Chrysoviridae family. Mycoviruses are (+)ssRNA and dsRNA genome viruses, which may or may not be enveloped. To date, no mycovirus with a DNA genome has been isolated from Colletotrichum spp. Typically, mycoviruses cause latent infections, although hypo- and hypervirulence have also been reported in Colletotrichum spp. In addition to its effects on pathogenic behavior, mycovirus infection can lead to important physiological changes, such as altered morphological characteristics, reduced vegetative growth, and suppressed conidia production. Therefore, research on mycoviruses infecting phytopathogenic fungi can help develop alternative methods to chemical control, which can cause irreversible damage to humans and the environment. From an agricultural perspective, mycoviruses can contribute to sustainable agriculture as biological control agents via changes in fungal physiology, ultimately resulting in the total loss of or reduction in the virulence of these pathogens.

Resumo Colletotrichum é um dos gêneros fúngicos mais importantes economicamente, afetando uma ampla gama de hospedeiros, especialmente em cultivos tropicais e subtropicais. Atualmente já existem diversos registros de infecção por micovírus em Colletotrichum spp., sendo a maioria dos já identificados classificados na família Partitiviridae. Ocorrem registros também de micovírus pertencentes à família Chrysoviridae. Compreendem vírus de genoma de (+)ssRNA e dsRNA que podem ser ou não envelopados. Ainda não foram identificados micovírus com genoma de DNA isolados de Colletotrichum. A infecção por micovírus pode ocorrer de forma latente, mas já foi observado em Colletotrichum spp. o fenômeno de hipo e hipervirulência. Além de influenciar no comportamento patogênico, a infecção pode causar mudanças fisiológicas importantes como alterações das características morfológicas, redução do crescimento vegetativo e redução na produção de conídios. O estudo com micovírus em fungos fitopatogênicos traz uma alternativa ao controle químico que é um método capaz de causar danos irreversíveis ao homem e o meio ambiente. Sob a perspectiva agrícola, os micovírus podem contribuir para agricultura sustentável como agentes de controle biológico. Isso porque obsevam-se mudanças importantes na fisiologia fúngica resultando na perda total ou redução da virulência desses patógenos.

Inhibition of Hedgehog signalling by NVP-LDE225 (Erismodegib) interferes with growth and invasion of human renal cell carcinoma cells.

BACKGROUND: Multiple lines of evidence support that the Hedgehog (Hh) signalling has a role in the maintenance and progression of different human cancers. Therefore, inhibition of the Hh pathway represents a valid anticancer therapeutic approach for renal cell carcinoma (RCC) patients. NVP-LDE225 is a Smoothened (Smo) antagonist that induces dose-related inhibition of Hh and Smo-dependent tumour growth. METHODS: We assayed the effects of NVP-LDE225 alone or in combination with everolimus or sunitinib on the growth and invasion of human RCC models both in vitro and in vivo. To this aim, we used a panel of human RCC models, comprising cells with acquired resistance to sunitinib - a multiple tyrosine kinase inhibitor approved as a first-line treatment for RCC. RESULTS: NVP-LDE225 cooperated with either everolimus or sunitinib to inhibit proliferation, migration, and invasion of RCC cells even in sunitinib-resistant (SuR) cells. Some major transducers involved in tumour cell motility, including paxillin, were also efficiently inhibited by the combination therapy, as demonstrated by western blot and confocal microscopy assays. Moreover, these combined treatments inhibited tumour growth and increased animal survival in nude mice xenografted with SuR RCC cells. Finally, lung micrometastasis formation was reduced when mice were treated with NVP-LDE225 plus everolimus or sunitinib, as evidenced by artificial metastatic assays. CONCLUSIONS: Hedgehog inhibition by NVP-LDE225 plus sunitinib or everolimus bolsters antitumour activity by interfering with tumour growth and metastatic spread, even in SuR cells. Thus, this new evidence puts forward a new promising therapeutic approach for RCC patients.

The dual PI3K/mTOR inhibitor PKI-587 enhances sensitivity to cetuximab in EGFR-resistant human head and neck cancer models.

BACKGROUND: Cetuximab is the only targeted agent approved for the treatment of head and neck squamous cell carcinomas (HNSCC), but low response rates and disease progression are frequently reported. As the phosphoinositide 3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) pathways have an important role in the pathogenesis of HNSCC, we investigated their involvement in cetuximab resistance. METHODS: Different human squamous cancer cell lines sensitive or resistant to cetuximab were tested for the dual PI3K/mTOR inhibitor PF-05212384 (PKI-587), alone and in combination, both in vitro and in vivo. RESULTS: Treatment with PKI-587 enhances sensitivity to cetuximab in vitro, even in the condition of epidermal growth factor receptor (EGFR) resistance. The combination of the two drugs inhibits cells survival, impairs the activation of signalling pathways and induces apoptosis. Interestingly, although significant inhibition of proliferation is observed in all cell lines treated with PKI-587 in combination with cetuximab, activation of apoptosis is evident in sensitive but not in resistant cell lines, in which autophagy is pre-eminent. In nude mice xenografted with resistant Kyse30 cells, the combined treatment significantly reduces tumour growth and prolongs mice survival. CONCLUSIONS: Phosphoinositide 3-kinase/mammalian target of rapamycin inhibition has an important role in the rescue of cetuximab resistance. Different mechanisms of cell death are induced by combined treatment depending on basal anti-EGFR responsiveness.

Angiogenic and signalling proteins correlate with sensitivity to sequential treatment in renal cell cancer.

BACKGROUND: We aimed to study key signalling proteins involved in angiogenesis and proliferation on the response to inhibitors of tyrosine kinases and mammalian target of rapamycin in first- and in second-line treatment of renal cell carcinoma (RCC). METHODS: In a panel of human RCC tumours, in vitro and in nude mice, we evaluated the effect of sunitinib, sorafenib and everolimus, alone and in sequence, on tumour growth and expression of signalling proteins involved in proliferation and resistance to treatment. RESULTS: We demonstrated that, as single agents, sunitinib, sorafenib and everolimus share similar activity in inhibiting cell proliferation, signal transduction and vascular endothelial growth factor (VEGF) secretion in different RCC models, both in vitro and in tumour xenografts. Pre-treatment with sunitinib reduced the response to subsequent sunitinib and sorafenib but not to everolimus. Inability by sunitinib to persistently inhibit HIF-1, VEGF and pMAPK anticipated treatment resistance in xenografted tumours. After first-line sunitinib, second-line treatment with everolimus was more effective than either sorafenib or rechallenge with sunitinib in interfering with signalling proteins, VEGF and interleukin-8, translating into a significant advantage in tumour growth inhibition and mice survival. CONCLUSION: We demonstrated that a panel of angiogenic and signalling proteins can correlate with the onset of resistance to sunitinib and the activity of everolimus in second line.

Toll-like receptor 9 agonist IMO cooperates with everolimus in renal cell carcinoma by interfering with tumour growth and angiogenesis.

BACKGROUND: Targeting the mammalian target of rapamycin by everolimus is a successful approach for renal cell carcinoma (RCC) therapy. The Toll-like receptor 9 agonist immune modulatory oligonucleotide (IMO) exhibits direct antitumour and antiangiogenic activity and cooperates with both epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) inhibitors. METHODS: We tested the combination of IMO and everolimus on models of human RCC with different Von-Hippel Lindau (VHL) gene status, both in vitro and in nude mice. We studied their direct antiangiogenic effects on human umbilical vein endothelial cells. RESULTS: Both IMO and everolimus inhibited in vitro growth and survival of RCC cell lines, and their combination produced a synergistic inhibitory effect. Moreover, everolimus plus IMO interfered with EGFR-dependent signaling and reduced VEGF secretion in both VHL wild-type and mutant cells. In RCC tumour xenografts, IMO plus everolimus caused a potent and long-lasting cooperative antitumour activity, with reduction of tumour growth, prolongation of mice survival and inhibition of signal transduction. Furthermore, IMO and everolimus impaired the main endothelial cell functions. CONCLUSION: A combined treatment with everolimus and IMO is effective in VHL wild-type and mutant models of RCC by interfering with tumour growth and angiogenesis, thus representing a potentially effective, rationale-based combination to be translated in the clinical setting.

KRAS mutation detection by high-resolution melting analysis significantly predicts clinical benefit of cetuximab in metastatic colorectal cancer.

BACKGROUND: Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies are restricted to KRAS wild-type (WT) metastatic colorectal cancers (mCRCs), usually identified by direct sequencing, that may yield false negative results because of genetic heterogeneity within the tumour. We evaluated the efficiency of high-resolution melting analysis (HRMA) in identifying KRAS-mutant (MUT) tumours. METHODS: We considered 50 mCRC patients scored as KRAS-WT by direct sequencing and treated with cetuximab-containing chemotherapy, and tested the correlations between HRMA findings and response rate (RR), progression-free (PFS) and overall survival (OS). RESULTS: Aberrant melting curves were detected in four (8%) cases; gene cloning confirmed these mutations. Response rate (RR) of HRMA KRAS-WT patients was 28.3%. There was no response in HRMA KRAS-MUT patients. Disease control rate (responsive plus stable disease) was 58.7% in HRMA KRAS-WT patients and 25% in HRMA KRAS-MUT patients. There was no correlation between HRMA KRAS status and RR (P=0.287) or disease control (P=0.219). Median PFS (4.8 vs 2.3 months; hazard ratio (HR)=0.29, P=0.02) and OS (11.0 vs 2.7 months; HR=0.11, P=0.03) were significantly longer for the HRMA KRAS-WT than for HRMA KRAS-MUT patients. CONCLUSIONS: High-resolution melting analysis identified 8% more KRAS-MUT patients not responding to cetuximab-containing regimens, suggesting that HRMA may be more effective than direct sequencing in selecting patients for anti-EGFR antibodies.

Severe haemophilia A patients have reduced numbers of peripheral memory B cells.

The development of inhibitors is a complication of replacement treatment in Haemophilia. Loss of factor VIII-specific memory B cells in the spleen is associated with down regulation of antibodies in mice treated with high doses of FVIII, but changes in B cell memory have not been described in haemophilic patients. The aim of this study was to evaluate the phenotype of circulating lymphocytes in severe haemophilia A. Twenty patients with inhibitors (PI), 22 without inhibitors (P), nine patients during immune tolerance induction (ITI) treatment and 20 healthy donors (HD) were included. Peripheral blood lymphocytes were examined using flow cytometry. Anti-FVIII antibodies were measured using Bethesda and flow cytometry. Percentages of T subsets and B lymphocytes were similar in all groups. In contrast, memory B cells (CD27+) were decreased in PI and P compared with HD, but the level of significance was higher in PI (P = 0.001) than P (P = 0.01). PI with high level of anti-FVIII antibodies presented the lowest B memory values. CD70 expression was also lowest in PI. Non-switched CD27+ subpopulation (IgD+) was prevalent in PI, but did not show statistical significance. When ITI failed, the percentages of CD27+ B cells after 12 months of ITI were lowest. In a longitudinal study performed in four patients, an increased percentage of CD27+ and CD70+ B cells during ITI was found. This work suggests that different peripheral lymphocyte markers, such as CD27 and CD70 on B cells, may be helpful to evaluate anti-FVIII response and to monitor the success of ITI.

Elective orthopaedic surgery for haemophilia patients with inhibitors: single centre experience of 40 procedures and review of the literature.

With the introduction of safe and effective factor VIII/IX-bypassing agents--recombinant activated factor VII (rFVIIa) and plasma-derived activated prothrombin complex concentrates (pd-APCC)--elective orthopaedic surgery (EOS) is a viable option for haemophilia patients with inhibitors. We report a series of patients with haemophilia and inhibitors undergoing EOS between 1997 and 2008 using bypassing agents to provide haemostatic cover. All inhibitor patients undergoing EOS and receiving rFVIIa, plasma-derived prothrombin complex concentrates (pd-PCC) or pd-APCC as haemostatic cover were included. Patients were operated on by the same surgeon and were managed by the same haemophilia treatment centre. Forty procedures (25 minor and 15 major) were conducted in 18 patients. Twenty-one minor cases were covered using rFVIIa, three with pd-PCC, and one with pd-APCC; all major cases were covered using rFVIIa. Bleeding was no greater than expected compared with a non-haemophilic population in all 25 minor procedures. In the major procedure group, there was no excessive bleeding in 40% of cases (6/15) and bleeding completely stopped in response to rFVIIa. For the remaining nine cases, bleeding response to rFVIIa was described as 'markedly decreased' or 'decreased' in 4/15 cases and 'unchanged' in 5/15 cases. Overall, efficacy of rFVIIa, based on final patient outcome, was 85%. One death occurred as a result of sepsis secondary to necrotizing fasciitis. Good control of haemostasis can be achieved with bypassing agents in haemophilia patients with inhibitors undergoing minor EOS; rFVIIa was used as an effective bypassing agent, enabling EOS in patients undergoing minor and major procedures.

Two novel human anti-ErbB2 immunoagents are active on trastuzumab-resistant tumours.

BACKGROUND: Overexpression of ErbB2 receptor in breast cancer is associated with disease progression and poor prognosis. Trastuzumab, the only humanised anti-ErbB2 antibody currently used in breast cancer, has proven to be effective; however, a relevant problem for clinical practice is that a high fraction of breast cancer patients shows primary or acquired resistance to trastuzumab treatment. METHODS: We tested on trastuzumab-resistant cells two novel human anti-tumour immunoconjugates engineered in our laboratory by fusion of a human anti-ErbB2 scFv, termed Erbicin, with either a human RNase or the Fc region of a human IgG1. Both Erbicin-derived immunoagents (EDIAs) are selectively cytotoxic for ErbB2-positive cancer cells in vitro and vivo, target an ErbB2 epitope different from that recognised by trastuzumab and do not show cardiotoxic effects. RESULTS: We report that EDIAs are active also on trastuzumab-resistant tumour cells both in vitro and in vivo, most likely because of the different epitope recognised, as EDIAs, unlike trastuzumab, were found to be able to inhibit the signalling pathway downstream of ErbB2. CONCLUSION: These results suggest that EDIAs are immunoagents that could not only fulfil the therapeutic need of patients ineligible to trastuzumab treatment due to cardiac dysfunction but also prove to be useful for breast cancer patients unresponsive to trastuzumab treatment.

Paraneoplastic sensitive neuropathy associated with anti-hu antibodies in a neuroendocrine tumor of duodenum: a case report.

Paraneoplastic sensitive neuropathy is one of the most common presentations among a group of cancer-related disorders known as Paraneoplastic Neurological Syndromes (PNS). PNS likely have an autoimmune etiology since they have been associated with the presence of antibodies against neuronal antigens expressed by tumor cells (such as anti-Hu, anti-Ri and anti-Yo). The tumors most frequently associated with PSN and onconeural antibodies are lung cancer, lymphomas and gynaecological tumors; however, they have also been described in other tumors. We report, for the first time, a case of neuroendocrine tumor of duodenum and PNS associated with anti-Hu antibodies. Moreover, we analyze and discuss the clinical implications that PNS and anti-Hu could have in patients with tumors.

Fenoldopam to prevent renal replacement therapy after cardiac surgery. Design of the FENO-HSR study.

INTRODUCTION: Acute kidney injury requiring renal replacement therapy is a serious complication following cardiac surgery associated with poor clinical outcomes. Until now no drug showed nephroprotective effects. Fenoldopam is a dopamine-1 receptor agonist which seems to be effective in improving postoperative renal function. The aim of this paper is to describe the design of the FENO-HSR study, planned to assess the effect of a continuous infusion of fenoldopam in reducing the need for renal replacement therapy in patients with acute kidney injury after cardiac surgery. METHODS: We're performing a double blind, placebo-controlled multicentre randomized trial in over 20 Italian hospitals. Patients who develop acute renal failure defined as R of RIFLE score following cardiac surgery are randomized to receive a 96-hours continuous infusion of either fenoldopam (0.025-0.3 µg/kg/min) or placebo. RESULTS: The primary endpoint will be the rate of renal replacement therapy. Secondary endpoints will be: mortality, time on mechanical ventilation, length of intensive care unit and hospital stay, peak serum creatinine and the rate of acute renal failure (following the RIFLE score). CONCLUSIONS: This trial is planned to assess if fenoldopam could improve relevant outcomes in patients undergoing cardiac surgery who develop acute renal dysfunction. Results of this double-blind randomized trial could provide important insights to improve the management strategy of patients at high risk for postoperative acute kidney injury.

[Vacuum-assisted breast biopsy for diagnosis of non-palpable lesions: experience with 226 cases]. / Biopsia mammaria "vacuum-assisted" per la diagnosi di lesioni non palpabili: descrizione dei primi 226 casi.

Vacuum-assisted breast biopsy (VABB) is now available for non-palpable lesions. The present study describes the results obtained from 226 consecutive VABBs performed at "L. Sacco" Hospital, Milan, from November 2005 to July 2007 (198 stereotactic and 28 ultrasonographic procedures). Adequate tissue samples for histopathological evaluation were obtained in 225 cases (99.6%). The diagnoses were as follows: 9 normal tissues (4%), 97 benign (43%), 25 "probably benign" (11%), 4 "suspicious for malignancy" (2%) and 90 malignant (40%, 53 in situ and 37 infiltrating carcinoma). Of the 90 malignant cases, 38 (42.2%) underwent subsequent surgical excision in our Unit; 84.2% (32/38) had concordant histopathological findings. In conclusion, VABB is an accurate and safe technique for diagnosis of non-palpable lesions, and in experienced hands avoids unnecessary surgical procedures.

Enzastaurin inhibits tumours sensitive and resistant to anti-EGFR drugs.

We investigated the antitumour effect and ability to overcome the resistance to anti-EGFR drugs of enzastaurin, an inhibitor of VEGFR-dependent PKCbeta signalling. Enzastaurin was evaluated alone and in combination with the EGFR inhibitor gefitinib, on growth and signalling protein expression in human cancer cells sensitive and resistant to anti-EGFR drugs, both in vitro and in nude mice. We demonstrated the marked inhibitory activity of enzastaurin against GEO colon and PC3 prostate cancer cells and their gefitinib-resistant counterparts GEO-GR and PC3-GR, accompanied by inhibition of pAkt and its effector pp70S6K, pGSK3beta and VEGF expression and secretion. Moreover, enzastaurin showed a cooperative effect with gefitinib in parental and in gefitinib-resistant cells. Remarkably, these results were confirmed in vivo, where enzastaurin showed antitumour activity and cooperativity with gefitinib in mice grafted with GEO and GEO-GR tumours, incrementing their median survival and inhibiting the aforesaid protein expression and secretion in tumour specimens. In conclusion, enzastaurin by interfering with signalling proteins implicated in EGFR drug resistance markedly cooperates with gefitinib in sensitive and gefitinib-resistant tumours, thus overcoming and reverting such resistance and providing a rational basis for its development in patients resistant to anti-EGFR drugs.

Inhibition of mTOR pathway by everolimus cooperates with EGFR inhibitors in human tumours sensitive and resistant to anti-EGFR drugs.

Inhibition of a single transduction pathway is often inefficient due to activation of alternative signalling. The mammalian target of rapamycin (mTOR) is a key intracellular kinase integrating proliferation, survival and angiogenic pathways and has been implicated in the resistance to EGFR inhibitors. Thus, mTOR blockade is pursued to interfere at multiple levels with tumour growth. We used everolimus (RAD001) to inhibit mTOR, alone or in combination with anti-EGFR drugs gefitinib or cetuximab, on human cancer cell lines sensitive and resistant to EGFR inhibitors, both in vitro and in vivo. We demonstrated that everolimus is active against EGFR-resistant cancer cell lines and partially restores the ability of EGFR inhibitors to inhibit growth and survival. Everolimus reduces the expression of EGFR-related signalling effectors and VEGF production, inhibiting proliferation and capillary tube formation of endothelial cells, both alone and in combination with gefitinib. Finally, combination of everolimus and gefitinib inhibits growth of GEO and GEO-GR (gefitinib resistant) colon cancer xenografts, activation of signalling proteins and VEGF secretion. Targeting mTOR pathway with everolimus overcomes resistance to EGFR inhibitors and produces a cooperative effect with EGFR inhibitors, providing a valid therapeutic strategy to be tested in a clinical setting.

The rationale for the combination of selective EGFR inhibitors with cytotoxic drugs and radiotherapy.

The epidermal growth factor receptor (EGFR) is frequently overexpressed in a wide range of human tumors; such overexpression often correlates with poor prognosis and worse clinical outcome. It has been demonstrated that the EGFR autocrine pathway plays a crucial role in human cancer since it contributes to a number of highly relevant processes in tumor development and progression, including cell proliferation, regulation of apoptotic cell death, angiogenesis and metastatic spread. For these reasons EGFR is one of the most studied and exploited targets for molecular cancer therapy. Two classes of anti-EGFR agents have entered clinical practice: monoclonal antibodies and small molecules targeting receptor tyrosine kinases. The possibility of combining conventional cytotoxic drugs with agents that specifically interfere with key pathways controlling cancer cell survival, proliferation, invasion and/or metastatic spread has generated wide interest. This could be a promising therapeutic approach for several reasons. First, the occurrence of cross-resistance is infrequent since the cellular targets and mechanisms of action of cytotoxic drugs and EGFR antagonists are different. Second, alterations in the expression and/or activity of genes that regulate mitogenic signals may either cause perturbation of cell growth or affect the sensitivity of cancer cells to conventional chemotherapy and radiotherapy. In fact, EGFR inhibitors have shown activity alone and/or in combination with conventional antitumor treatments.

Haemophilic pseudotumour of the mandible: report of three cases.

A haemophilic pseudotumour is basically an encapsulated haematoma. It is an infrequent complication, estimated to affect 1-2% of severe haemophiliacs, although it has also been reported in patients with mild and moderate haemophilia. A history of trauma is reported in most cases, and the onset of symptoms varies from months to years. The majority of haemophilic pseudotumours are seen in adults and occur in long bones (femur, pelvis, tibia). Here are reported three cases of pseudotumour of the mandible in young patients with mild haemophilia A.