Analysis of the interaction between the IGF system and HIF: rationale for cotargeting the two systems in breast cancer.

The observation that several RTKs can act as promoters of tumor development and growth has brought a revolution in the study of new targets, in the hope of developing more specific anticancer drugs: the Insulin-like Growth Factors system is among the most studied. The role of this system in the development and progression of a large number of malignancies is well documented. Hence the development of different classes of compounds that can affect this system, in particular directly targeting the type 1 receptor (IGF-1R). Some of these compounds, both monoclonal antibodies (mAbs) against the receptor or small molecules that inhibit the TK activity of IGF-1R, are already undergoing clinical trials, because of their effectiveness in inhibiting the signal. Unfortunately, cancer cells show a high degree of plasticity and redundancy in the proliferative and anti-apoptotic signals, which may contribute to the creation of resistance to specific inhibitors: the identification of these mechanisms, and their overcome, are two key goals in the development of these drugs. Within this study, we encountered a similar problem: our experiments show that the compound in use, NVP-AEW541 (a specific, low molecular weight inhibitor of IGF-1R catalytic activity), is perfectly capable of inhibiting the signal transduced by the receptor following stimulation with IGF-1, but it appears to lose effectiveness following stimulation with IGF-2. Starting from the observation that IGF- 2 seems to be the key factor in this resistance, literature search showed us a growing number of experimental evidences in support of the role of variant A of the insulin receptor (IR-A) in the maintenance of a proliferative signal similar to that classically attributed to IGF-1R: our experiments confirmed the activation of this receptor following exposure to IGF-2, justifying the loss of effectiveness of NVP-AEW541 in regard of the migratory potential of MDA-231 cell line. While the dual inhibition of IGF-1R and IR could overcome this redundancy in the signal, it remains to consider the problems that may occur due to the inhibition of a receptor as essential for cellular metabolism as IR. A different and probably more practicable strategy would be the inhibition of the key player in the dual activation, IGF-2. The one proposed is a strategy that reflects the physiological mechanism of controlling the levels of IGF-2: in fact normal cells are able to control the levels of circulating IGF-2 by binding the ligand to IGF-2R, followed by its subsequent transport to lysosomes for degradation. During this study we then concentrated also on IGF-2R, observing no significative differences between the cell lines in study. Following the ligand-based targeting of the IGF system, which effectiveness seems to be proven by an ongoing phase I clinical trial using MEDI-573, actually the only mAb in clinical testing that exerts its effects by neutralizing not only IGF-2 but also IGF-1, we used a neutralizing antibody against IGF- 2 (MAB292), making it impossible for it to bind both IGF-1R and IR-A. The use of MAB292 proved to be effective both in combination with NVP-AEW541 and alone: MDA-231 cells seem in fact unable to respond to stimulation with IGF-2 and almost completely lose the ability to migrate. This strategy could be particularly effective especially considering that, in hypoxic conditions (pO2 <2.5%), stabilization of HIF-1α leads to an increase in the levels of IGF-2. This increase in fact results in the resistance of MDA-231 to NVP-AEW541, while MAB292 still retain its effectiveness. We also observed the lack of a direct and defined relationship between HIF-1α and IGF-2R levels: cells seemed not able to compensate to IGF-2 increase by increasing also the receptor levels. From this observation it’s therefore evident that another strategy to overcome the resistance to IGF-1R inhibitors may be the combination with HIF-1α inhibitors. At the present days, the fundamental problem is the lack of specific inhibitors: many chemotherapic drugs, in fact, have a complete or partial inhibitory activity of HIF-1α, that is however accompanied by a number of off-target effects. One of these compounds is Topotecan, a Top-1 poison in use in the treatment of ovarian and small cell lung cancer that inhibits HIF-1α translation by a Top1-dependent but DNA damage-independent mechanism, suggesting that its effect as HIF-1α inhibitor could be mechanistically distinguished from those characterizing its cytotoxic activity. In our case the dual inhibition was obtained with success through the use of Topotecan in combination with NVP-AEW541. We also introduced the combination between NVP-AEW541 and Luteolin, a compound of natural origin belonging to the flavonoid class that possess anti-proliferative and anti-migratory activity. Despite the more complex comprehension of its effect on HIF-1, which resulted only slightly decreased, the most interesting feature of this compound resulted to be its anti-migratory potential: the use of Luteolin in fact completely inhibited migration in MDA-231. As a last point in our study, we focused our attention on the metabolic alteration determined by the modulation of insulin/IGF system. Since deregulation of cellular energy metabolism is considered an increasingly important hallmark of cancer, IR and its related metabolic syndromes have become another major focus in the breast cancer research and treatment field. Preliminary analysis of the oxidative and glycolitic profiles of three cell lines showed in first stance an interesting difference at the basal level as well as a modulation of the two processes after treatment with NVP-AEW541 together with MAB292 or with Luteolin. Further experiments would be needed to assess the effective impact of these compounds on cellular metabolism, as well as the metabolic processes and responses in hypoxia. In conclusion we can say that the dual targeting of IGF-1R and HIF-1 appears to be an interesting therapeutic strategy in breast cancer, especially given the close relationship between these two systems

Analysis of the interaction between the IGF system and HIF: rationale for cotargeting the two systems in breast cancer.

The observation that several RTKs can act as promoters of tumor development and growth has brought a revolution in the study of new targets, in the hope of developing more specific anticancer drugs: the Insulin-like Growth Factors system is among the most studied. The role of this system in the development and progression of a large number of malignancies is well documented. Hence the development of different classes of compounds that can affect this system, in particular directly targeting the type 1 receptor (IGF-1R). Some of these compounds, both monoclonal antibodies (mAbs) against the receptor or small molecules that inhibit the TK activity of IGF-1R, are already undergoing clinical trials, because of their effectiveness in inhibiting the signal. Unfortunately, cancer cells show a high degree of plasticity and redundancy in the proliferative and anti-apoptotic signals, which may contribute to the creation of resistance to specific inhibitors: the identification of these mechanisms, and their overcome, are two key goals in the development of these drugs. Within this study, we encountered a similar problem: our experiments show that the compound in use, NVP-AEW541 (a specific, low molecular weight inhibitor of IGF-1R catalytic activity), is perfectly capable of inhibiting the signal transduced by the receptor following stimulation with IGF-1, but it appears to lose effectiveness following stimulation with IGF-2. Starting from the observation that IGF- 2 seems to be the key factor in this resistance, literature search showed us a growing number of experimental evidences in support of the role of variant A of the insulin receptor (IR-A) in the maintenance of a proliferative signal similar to that classically attributed to IGF-1R: our experiments confirmed the activation of this receptor following exposure to IGF-2, justifying the loss of effectiveness of NVP-AEW541 in regard of the migratory potential of MDA-231 cell line. While the dual inhibition of IGF-1R and IR could overcome this redundancy in the signal, it remains to consider the problems that may occur due to the inhibition of a receptor as essential for cellular metabolism as IR. A different and probably more practicable strategy would be the inhibition of the key player in the dual activation, IGF-2. The one proposed is a strategy that reflects the physiological mechanism of controlling the levels of IGF-2: in fact normal cells are able to control the levels of circulating IGF-2 by binding the ligand to IGF-2R, followed by its subsequent transport to lysosomes for degradation. During this study we then concentrated also on IGF-2R, observing no significative differences between the cell lines in study. Following the ligand-based targeting of the IGF system, which effectiveness seems to be proven by an ongoing phase I clinical trial using MEDI-573, actually the only mAb in clinical testing that exerts its effects by neutralizing not only IGF-2 but also IGF-1, we used a neutralizing antibody against IGF- 2 (MAB292), making it impossible for it to bind both IGF-1R and IR-A. The use of MAB292 proved to be effective both in combination with NVP-AEW541 and alone: MDA-231 cells seem in fact unable to respond to stimulation with IGF-2 and almost completely lose the ability to migrate. This strategy could be particularly effective especially considering that, in hypoxic conditions (pO2 <2.5%), stabilization of HIF-1\u3b1 leads to an increase in the levels of IGF-2. This increase in fact results in the resistance of MDA-231 to NVP-AEW541, while MAB292 still retain its effectiveness. We also observed the lack of a direct and defined relationship between HIF-1\u3b1 and IGF-2R levels: cells seemed not able to compensate to IGF-2 increase by increasing also the receptor levels. From this observation it\u2019s therefore evident that another strategy to overcome the resistance to IGF-1R inhibitors may be the combination with HIF-1\u3b1 inhibitors. At the present days, the fundamental problem is the lack of specific inhibitors: many chemotherapic drugs, in fact, have a complete or partial inhibitory activity of HIF-1\u3b1, that is however accompanied by a number of off-target effects. One of these compounds is Topotecan, a Top-1 poison in use in the treatment of ovarian and small cell lung cancer that inhibits HIF-1\u3b1 translation by a Top1-dependent but DNA damage-independent mechanism, suggesting that its effect as HIF-1\u3b1 inhibitor could be mechanistically distinguished from those characterizing its cytotoxic activity. In our case the dual inhibition was obtained with success through the use of Topotecan in combination with NVP-AEW541. We also introduced the combination between NVP-AEW541 and Luteolin, a compound of natural origin belonging to the flavonoid class that possess anti-proliferative and anti-migratory activity. Despite the more complex comprehension of its effect on HIF-1, which resulted only slightly decreased, the most interesting feature of this compound resulted to be its anti-migratory potential: the use of Luteolin in fact completely inhibited migration in MDA-231. As a last point in our study, we focused our attention on the metabolic alteration determined by the modulation of insulin/IGF system. Since deregulation of cellular energy metabolism is considered an increasingly important hallmark of cancer, IR and its related metabolic syndromes have become another major focus in the breast cancer research and treatment field. Preliminary analysis of the oxidative and glycolitic profiles of three cell lines showed in first stance an interesting difference at the basal level as well as a modulation of the two processes after treatment with NVP-AEW541 together with MAB292 or with Luteolin. Further experiments would be needed to assess the effective impact of these compounds on cellular metabolism, as well as the metabolic processes and responses in hypoxia. In conclusion we can say that the dual targeting of IGF-1R and HIF-1 appears to be an interesting therapeutic strategy in breast cancer, especially given the close relationship between these two systems

Analysis of the interaction between the IGF system and HIF: rationale for cotargeting the two systems in breast cancer.

The observation that several RTKs can act as promoters of tumor development and growth has brought a revolution in the study of new targets, in the hope of developing more specific anticancer drugs: the Insulin-like Growth Factors system is among the most studied. The role of this system in the development and progression of a large number of malignancies is well documented. Hence the development of different classes of compounds that can affect this system, in particular directly targeting the type 1 receptor (IGF-1R). Some of these compounds, both monoclonal antibodies (mAbs) against the receptor or small molecules that inhibit the TK activity of IGF-1R, are already undergoing clinical trials, because of their effectiveness in inhibiting the signal. Unfortunately, cancer cells show a high degree of plasticity and redundancy in the proliferative and anti-apoptotic signals, which may contribute to the creation of resistance to specific inhibitors: the identification of these mechanisms, and their overcome, are two key goals in the development of these drugs. Within this study, we encountered a similar problem: our experiments show that the compound in use, NVP-AEW541 (a specific, low molecular weight inhibitor of IGF-1R catalytic activity), is perfectly capable of inhibiting the signal transduced by the receptor following stimulation with IGF-1, but it appears to lose effectiveness following stimulation with IGF-2. Starting from the observation that IGF- 2 seems to be the key factor in this resistance, literature search showed us a growing number of experimental evidences in support of the role of variant A of the insulin receptor (IR-A) in the maintenance of a proliferative signal similar to that classically attributed to IGF-1R: our experiments confirmed the activation of this receptor following exposure to IGF-2, justifying the loss of effectiveness of NVP-AEW541 in regard of the migratory potential of MDA-231 cell line. While the dual inhibition of IGF-1R and IR could overcome this redundancy in the signal, it remains to consider the problems that may occur due to the inhibition of a receptor as essential for cellular metabolism as IR. A different and probably more practicable strategy would be the inhibition of the key player in the dual activation, IGF-2. The one proposed is a strategy that reflects the physiological mechanism of controlling the levels of IGF-2: in fact normal cells are able to control the levels of circulating IGF-2 by binding the ligand to IGF-2R, followed by its subsequent transport to lysosomes for degradation. During this study we then concentrated also on IGF-2R, observing no significative differences between the cell lines in study. Following the ligand-based targeting of the IGF system, which effectiveness seems to be proven by an ongoing phase I clinical trial using MEDI-573, actually the only mAb in clinical testing that exerts its effects by neutralizing not only IGF-2 but also IGF-1, we used a neutralizing antibody against IGF- 2 (MAB292), making it impossible for it to bind both IGF-1R and IR-A. The use of MAB292 proved to be effective both in combination with NVP-AEW541 and alone: MDA-231 cells seem in fact unable to respond to stimulation with IGF-2 and almost completely lose the ability to migrate. This strategy could be particularly effective especially considering that, in hypoxic conditions (pO2 <2.5%), stabilization of HIF-1α leads to an increase in the levels of IGF-2. This increase in fact results in the resistance of MDA-231 to NVP-AEW541, while MAB292 still retain its effectiveness. We also observed the lack of a direct and defined relationship between HIF-1α and IGF-2R levels: cells seemed not able to compensate to IGF-2 increase by increasing also the receptor levels. From this observation it’s therefore evident that another strategy to overcome the resistance to IGF-1R inhibitors may be the combination with HIF-1α inhibitors. At the present days, the fundamental problem is the lack of specific inhibitors: many chemotherapic drugs, in fact, have a complete or partial inhibitory activity of HIF-1α, that is however accompanied by a number of off-target effects. One of these compounds is Topotecan, a Top-1 poison in use in the treatment of ovarian and small cell lung cancer that inhibits HIF-1α translation by a Top1-dependent but DNA damage-independent mechanism, suggesting that its effect as HIF-1α inhibitor could be mechanistically distinguished from those characterizing its cytotoxic activity. In our case the dual inhibition was obtained with success through the use of Topotecan in combination with NVP-AEW541. We also introduced the combination between NVP-AEW541 and Luteolin, a compound of natural origin belonging to the flavonoid class that possess anti-proliferative and anti-migratory activity. Despite the more complex comprehension of its effect on HIF-1, which resulted only slightly decreased, the most interesting feature of this compound resulted to be its anti-migratory potential: the use of Luteolin in fact completely inhibited migration in MDA-231. As a last point in our study, we focused our attention on the metabolic alteration determined by the modulation of insulin/IGF system. Since deregulation of cellular energy metabolism is considered an increasingly important hallmark of cancer, IR and its related metabolic syndromes have become another major focus in the breast cancer research and treatment field. Preliminary analysis of the oxidative and glycolitic profiles of three cell lines showed in first stance an interesting difference at the basal level as well as a modulation of the two processes after treatment with NVP-AEW541 together with MAB292 or with Luteolin. Further experiments would be needed to assess the effective impact of these compounds on cellular metabolism, as well as the metabolic processes and responses in hypoxia. In conclusion we can say that the dual targeting of IGF-1R and HIF-1 appears to be an interesting therapeutic strategy in breast cancer, especially given the close relationship between these two systems

Designing multifunctional devices for regenerative pharmacology based on 3D scaffolds, drug-loaded nanoparticles, and thermosensitive hydrogels: a proof-of-concept study

Regenerative pharmacology combines tissue engineering/regenerative medicine (TERM) with drug delivery with the aim to improve the outcomes of traditional TERM approaches. In this work, we aimed to design a multicomponent TERM platform comprising a three-dimensional scaffold, a thermosensitive hydrogel, and drug-loaded nanoparticles. We used a thermally induced phase separation method to obtain scaffolds with anisotropic mechanical properties, suitable for soft tissue engineering. A thermosensitive hydrogel was developed using a Poloxamer® 407-based poly(urethane) to embed curcumin-loaded nanoparticles, obtained by the single emulsion nanoprecipitation method. We found that encapsulated curcumin could retain its antioxidant activity and that embedding nanoparticles within the hydrogel did not affect the hydrogel gelation kinetics nor the possibility to progressively release the drug. The porous scaffold was easily loaded with the hydrogel, resulting in significantly enhanced (4-fold higher) absorption of a model molecule of nutrients (fluorescein isothiocyanate dextran 4kDa) from the surrounding environment compared to pristine scaffold. The developed platform could thus represent a valuable alternative in the treatment of many pathologies affecting soft tissues, by concurrently exploiting the therapeutic effects of drugs, with the 3D framework acting as a physical support for tissue regeneration and the cell-friendly environment represented by the hydrogel

The direct association of the multiple PDZ domain containing proteins (MUPP-1) with the human c-Kit C-terminus is regulated by tyrosine kinase activity

AbstractWe have identified the multiple PDZ domain containing protein (MUPP-1 or MPDZ) as a novel binding partner of the human c-Kit. c-Kit binds specifically to the 10th PDZ domain of MUPP-1 via its C-terminal sequence. Furthermore, a kinase negative-mutant receptor interacted more strongly with MUPP-1 than the wild-type c-Kit. Strikingly, a constitutively activated c-Kit (D816V-Kit) did not bind to MUPP-1, although this oncogenic form retains the PDZ binding motif ‘HDDV’ at the C-terminal end. Deletion of V967 of c-Kit abolished binding to MUPP-1 and drastically reduced its tyrosine kinase activity, suggesting that the structure of the C-terminal tail of c-Kit influences its enzymatic activity

Dopamine Transmission Imbalance in Neuroinflammation: Perspectives on Long-Term COVID-19

Dopamine (DA) is a key neurotransmitter in the basal ganglia, implicated in the control of movement and motivation. Alteration of DA levels is central in Parkinson's disease (PD), a common neurodegenerative disorder characterized by motor and non-motor manifestations and deposition of alpha-synuclein (alpha-syn) aggregates. Previous studies have hypothesized a link between PD and viral infections. Indeed, different cases of parkinsonism have been reported following COVID-19. However, whether SARS-CoV-2 may trigger a neurodegenerative process is still a matter of debate. Interestingly, evidence of brain inflammation has been described in postmortem samples of patients infected by SARS-CoV-2, which suggests immune-mediated mechanisms triggering the neurological sequelae. In this review, we discuss the role of proinflammatory molecules such as cytokines, chemokines, and oxygen reactive species in modulating DA homeostasis. Moreover, we review the existing literature on the possible mechanistic interplay between SARS-CoV-2-mediated neuroinflammation and nigrostriatal DAergic impairment, and the cross-talk with aberrant alpha-syn metabolism

Anti-carbamylated protein antibodies as a new biomarker of erosive joint damage in systemic lupus erythematosus

Background: The application of more sensitive imaging techniques, such as ultrasonography (US), changed the concept of non-erosive arthritis in systemic lupus erythematosus (SLE), underlining the need for biomarkers to identify patients developing the erosive phenotype. Anti-citrullinated peptide antibodies (ACPA), associated with erosions in inflammatory arthritis, have been identified in about 50% of patients with SLE with erosive arthritis. More recently, anti-carbamylated proteins antibodies (anti-CarP) have been associated with erosive damage in rheumatoid arthritis. We aimed to assess the association between anti-CarP and erosive damage in a large SLE cohort with joint involvement. Methods: We evaluated 152 patients (male/female patients 11/141; median age 46years, IQR 16; median disease duration 108months, IQR 168). All patients underwent blood draw to detect rheumatoid factor (RF) and ACPA (commercial enzyme-linked immunosorbent assay (ELISA) kit), and anti-CarP ("home-made" ELISA, cutoff 340aU/mL). The bone surfaces of the metacarpophalangeal and proximal interphalangeal joints were assessed by US: the presence of erosions was registered as a dichotomous value (0/1), obtaining a total score (0-20). Results: The prevalence of anti-CarP was 28.3%, similar to RF (27.6%) and significantly higher than ACPA (11.2%, p=0.003). Erosive arthritis was identified in 25.6% of patients: this phenotype was significantly associated with anti-CarP (p=0.004). Significant correlation between anti-CarP titer and US erosive score was observed (r=0.2, p=0.01). Conclusions: Significant association was identified between anti-CarP and erosive damage in SLE-related arthritis, in terms of frequency and severity, suggesting that these antibodies can represent a biomarker of severity in patients with SLE with joint involvement

Expression of Autophagic and Inflammatory Markers in Normal Mucosa of Individuals with Colorectal Adenomas: A Cross Sectional Study among Italian Outpatients Undergoing Colonoscopy

: Colorectal cancer (CRC) ranks among the three most common cancers in terms of both cancer incidence and cancer-related deaths in Western industrialized countries. Lifetime risk of colorectal cancer may reach 6% of the population living in developed countries. In the current era of personalized medicine, CRC is no longer considered as a single entity. In more recent years many studies have described the distinct differences in epidemiology, pathogenesis, genetic and epigenetic alterations, molecular pathways and outcome depending on the anatomical site. The aim of our study is to assess in a multidimensional model the association between metabolic status and inflammatory and autophagic changes in the normal colorectal mucosa classified as right-sided, left-sided and rectum, and the presence of adenomas. One hundred and sixteen patients undergoing colonoscopy were recruited and underwent a complete serum lipid profile, immunofluorescence analysis of colonic biopsies for MAPLC3 and myeloperoxidase expression, matched with clinical and anthropometric characteristics. Presence of adenomas correlated with cholesterol (total and LDL) levels, IL-6 levels, and MAPLC3 tissue expression, especially in the right colon. In conclusion, serum IL-6 amount and autophagic markers could be good predictors of the presence of colorectal adenomas

The radiosensitizing effect of Ku70/80 knockdown in MCF10A cells irradiated with X-rays and p(66)+Be(40) neutrons

Background: A better understanding of the underlying mechanisms of DNA repair after low-and high-LET radiations represents a research priority aimed at improving the outcome of clinical radiotherapy. To date however, our knowledge regarding the importance of DNA DSB repair proteins and mechanisms in the response of human cells to high-LET radiation, is far from being complete. Methods: We investigated the radiosensitizing effect after interfering with the DNA repair capacity in a human mammary epithelial cell line (MCF10A) by lentiviral-mediated RNA interference (RNAi) of the Ku70 protein, a key-element of the non-homologous end-joining (NHEJ) pathway. Following irradiation of control and Ku-deficient cell lines with either 6 MV X-rays or p(66)+Be(40) neutrons, cellular radiosensitivity testing was performed using a crystal violet cell proliferation assay. Chromosomal radiosensitivity was evaluated using the micronucleus (MN) assay. Results: RNAi of Ku70 caused downregulation of both the Ku70 and the Ku80 proteins. This downregulation sensitized cells to both X-rays and neutrons. Comparable dose modifying factors (DMFs) for X-rays and neutrons of 1.62 and 1.52 respectively were obtained with the cell proliferation assay, which points to the similar involvement of the Ku heterodimer in the cellular response to both types of radiation beams. After using the MN assay to evaluate chromosomal radiosensitivity, the obtained DMFs for X-ray doses of 2 and 4 Gy were 2.95 and 2.66 respectively. After neutron irradiation, the DMFs for doses of 1 and 2 Gy were 3.36 and 2.82 respectively. The fact that DMFs are in the same range for X-rays and neutrons confirms a similar importance of the NHEJ pathway and the Ku heterodimer for repairing DNA damage induced by both X-rays and p(66)+Be(40) neutrons. Conclusions: Interfering with the NHEJ pathway enhanced the radiosensitivity of human MCF10A cells to low-LET Xrays and high-LET neutrons, pointing to the importance of the Ku heterodimer for repairing damage induced by both types of radiation. Further research using other high-LET radiation sources is however needed to unravel the involvement of DNA double strand break repair pathways and proteins in the cellular response of human cells to high-LET radiation

Effect of mechanical separation process on lipid oxidation in European aquacultured sea bass, gilthead sea bream, and rainbow trout products

Mechanical separation systems are a good option to create new fish products and open new market, however studies on the effect on quality of mechanical treatment on species of interest for European aquaculture, such as European sea bass, gilthead sea bream, and rainbow trout are scarce. Thus in this research, the effect on colour, nutritional quality, and lipid stability was considered immediately after separation process and after 90 days of frozen storage. Results revealed that mechanical separation technique significantly affected colour and lipid stability of the three studied species. Increases in L* and secondary oxidation products were observed, together with a decrease of antioxidant capacity. Nutritional value instead was unaffected by treatment. Thus, mechanical separation process could represent a new way to better exploit species of interest for European aquaculture and acquire new market niches, but oxidative processes during the treatment have to be limited and kept under control