Glioblastoma multiforme (GBM), or grade IV astrocytoma, is the most common type of primary brain tumor. It has a devastating prognosis with a 2-year-overall survival rate of only 26 % after standard ...treatment, which includes surgery, radiation, and adjuvant chemotherapy with temozolomide. Also lower grade gliomas are difficult to treat, because they diffusely spread into the brain, where extensive removal of tissue is critical. Better understanding of the cancer’s biology is a key for the development of more effective therapy approaches. The discovery of isocitrate dehydrogenase (IDH) mutations in leukemia and glioma drew attention to specific metabolic aberrations in IDH-mutant gliomas. In the center of the metabolic alterations is α-ketoglutarate (αKG), an intermediate metabolite in the tricarboxylic acid (TCA) cycle, and the associated amino acid glutamate (Glu). This article highlights the role of these metabolites in glioma energy and lipid production and indicates possible weak spots of IDH-mutant and IDH-wt gliomas.
Gemcitabine is an antimetabolite ranking among the most prescribed anticancer drugs worldwide. This nucleoside analog exerts its antiproliferative action after tumoral conversion into active ...triphosphorylated nucleotides interfering with DNA synthesis and targeting ribonucleotide reductase. Gemcitabine is a mainstay for treating pancreatic and lung cancers, alone or in combination with several cytotoxic drugs (nab-paclitaxel, cisplatin and oxaliplatin), and is an option in a variety of other solid or hematological cancers. Several determinants of response have been identified with gemcitabine, i.e., membrane transporters, activating and inactivating enzymes at the tumor level, or Hedgehog signaling pathway. More recent studies have investigated how germinal genetic polymorphisms affecting cytidine deaminase, the enzyme responsible for the liver disposition of gemcitabine, could act as well as a marker for clinical outcome (i.e., toxicity, efficacy) at the bedside. Besides, constant efforts have been made to develop alternative chemical derivatives or encapsulated forms of gemcitabine, as an attempt to improve its metabolism and pharmacokinetics profile. Overall, gemcitabine is a drug paradigmatic for constant searches of the scientific community to improve its administration through the development of personalized medicine in oncology.
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a notably poor prognosis, in urgent need of improved treatment strategies. The desmoplastic PDAC tumor microenvironment (TME), ...marked by a high concentration of cancer-associated-fibroblasts (CAFs), is a dynamic part of PDAC pathophysiology which occasions a variety of effects throughout the course of pancreatic tumorigenesis and disease evolution. A better understanding of the desmoplastic TME and CAF biology in particular, should provide new opportunities for improving therapeutics. That CAFs have a tumor-supportive role in oncogenesis is well known, yet research evidence has shown that CAFs also have tumor-repressive functions. In this review, we seek to clarify the intriguing heterogeneity and plasticity of CAFs and their ambivalent role in PDAC tumorigenesis and progression. Additionally, we provide recommendations to advance the implementation of CAF-directed PDAC care. An improved understanding of CAFs’ origins, spatial location, functional diversity, and marker determination, as well as CAF behavior during the course of PDAC progression and metastasis will provide essential knowledge for the future improvement of therapeutic strategies for patients suffering from PDAC.
In early 2000, the term 'targeted therapy' became popular and was used to indicate all types of tyrosine kinase inhibitors (TKI). However, the term targeted therapy had been used much earlier. ...Targeting tumor metabolism was already considered as targeted therapy, with methotrexate and 5-fluorouracil as the most successful examples. Hormone therapy is another successful type of targeted therapy. Imatinib was the first TKI for the fusion protein BCR-ABL and represented a breakthrough in the treatment of chronic myeloid leukemia. Many other TKIs have been introduced into the clinic, but most were less specific and had multiple targets, and therefore, by definition, not targeted. However, with the introduction of TKIs developed specifically against mutations in the active site of a TK, more truly targeted TKI have been approved, such as new anaplastic lymphoma kinase - echinoderm microtubule-associated protein-like 4 (ALK-EML4) inhibitors and the epidermal growth factor-T790M-targeted osimertinib. This article summarizes the content of the Burger-Kelland award lecture given by the Author in February 2019 during the 40th EORTC-PAMM Group meeting in Verona, Italy and reviews the development of various targeted agents.
Neurotoxicity is a burdensome side effect of platinum‐based chemotherapy that prevents administration of the full efficacious dosage and often leads to treatment withdrawal. Peripheral sensory ...neurotoxicity varies from paresthesia in fingers to ataxic gait, which might be transient or irreversible. Because the number of patients being treated with these neurotoxic agents is still increasing, the need for understanding the pathogenesis of this dramatic side effect is critical. Platinum derivatives, such as cisplatin and carboplatin, harm mainly peripheral nerves and dorsal root ganglia neurons, possibly because of progressive DNA‐adduct accumulation and inhibition of DNA repair pathways (e.g., extracellular signal‐regulated kinase 1/2, c‐Jun N‐terminal kinase/stress‐activated protein kinase, and p38 mitogen‐activated protein kinass), which finally mediate apoptosis. Oxaliplatin, with a completely different pharmacokinetic profile, may also alter calcium‐sensitive voltage‐gated sodium channel kinetics through a calcium ion immobilization by oxalate residue as a calcium chelator and cause acute neurotoxicity. Polymorphisms in several genes, such as voltage‐gated sodium channel genes or genes affecting the activity of pivotal metal transporters (e.g., organic cation transporters, organic cation/carnitine transporters, and some metal transporters, such as the copper transporters, and multidrug resistance‐associated proteins), can also influence drug neurotoxicity and treatment response. However, most pharmacogenetics studies need to be elucidated by robust evidence. There are supportive reports about the effectiveness of several neuroprotective agents (e.g., vitamin E, glutathione, amifostine, xaliproden, and venlafaxine), but dose adjustment and/or drug withdrawal seem to be the most frequently used methods in the management of platinum‐induced peripheral neurotoxicity. To develop alternative options in the treatment of platinum‐induced neuropathy, studies on in vitro models and appropriate trials planning should be integrated into the future design of neuroprotective strategies to find the best patient‐oriented solution.
This review summarizes preclinical and clinical evidence of pathogenesis and pathophysiology of platinum‐induced peripheral neurotoxicity, as well as available evidence of neuroprotective and therapeutic strategies. These data may help to develop alternative options in the treatment of platinum‐induced neuropathy, studies on in vitro models, and appropriate trials planning to find the best patient‐oriented solution.
DUP-785 (Brequinar sodium) is a potent inhibitor of the mitochondrial dihydroorotate dehydrogenase (DHO-DH), a rate-limiting enzyme in the pyrimidine de novo nucleotide synthesis. In phase I clinical ...studies at the maximum tolerated dose (MTD) Brequinar induced a long-term inhibition of DHO-DH in white blood cells (WBC) and a long-term depletion of plasma uridine. These two parameters were related to severe myelosuppression, so that in Phase II studies the dose of Brequinar was decreased considerably. We further characterized the mechanism of DHO-DH enzyme inhibition while in blood samples of patients entered into Phase II studies we evaluated DHO-DH inhibition in WBC and plasma uridine depletion. With Electron Spin Resonance it was demonstrated that DHO-DH produced oxygen radical formation, which was inhibited by Brequinar. In the Phase II study depending on the dose (600 to 2000 mg/m
2
), uridine decreased to 20% (at the highest dose) or to 80-85% (at the middle dose) or did not change, which was associated with inhibition of DHO-DH (1% activity left vs 11 and 24% left). Inhibition of DHO-DH in the tumor of the latter patient was moderate as well (12% activity left). Brequinar was inactive in all tumor types evaluated possibly because of high uridine levels in the tumor. In conclusion, Brequinar was inactive against solid tumors, but DHO-DH inhibition was associated with myeloid toxicity, which may explain its potential for treatment of leukemia or inflammatory diseases.
AIM To critically assess the available literature regarding the efficacy of thioguanine treatment in inflammatory bowel disease(IBD) patients, irrespective of the(hepato-) toxicity profile.METHODS A ...systematic literature search of the MEDLINE database using Pub Med was performed using the keywords 'thioguanine', '6-TG', 'thioguanine', 'inflammatory bowel disease', 'IBD', 'Crohn’s disease', 'Ulcerative colitis' and 'effectiveness' in order to identify relevant articles published in English starting from 2000. Reference lists of the included articles were crosschecked for missing articles. Reviewed manuscripts concerning the effectiveness of thioguanine treatment in IBD were reviewed by the authors and the data were extracted. Data were subsequently analyzed with descriptive statistics. Due to the lack of standardized outcomes, a formal meta-analysis was not performed.RESULTS A total of 11 applicable studies were found that involved the effectiveness of thioguanine therapy in IBD. Eight studies were conducted in a prospectivemanner, in the remaining three studies, data was collected retrospectively. In total, 353 IBD-patients(225 patients with Crohn’s disease, 119 with ulcerative colitis and nine with unclassified IBD) with prior azathioprine/mercaptopurine resistance and/or intolerance(n = 321) or de novo thioguanine administration(n = 32) were included for analysis, of which 228(65%) had clinical improvement on thioguanine therapy, based on standard IBD questionnaires, biochemical parameters or global physician assessments. Short-term results were based on 268 treatment years(median follow-up 9 mo, range 3-22 mo) with a median daily dose of 20 mg(range 10-80 mg). Discontinuation, mostly due to adverse events, was reported in 72 patients(20%). CONCLUSION The efficacy of thioguanine therapy in IBD patients intolerant to conventional thiopurine therapy is observed in 65%, with short term adverse events in 20% of patients.
Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. The high risk of recurrence following surgical resection provides the rationale for adjuvant therapy. However, only a subset of ...patients benefit from adjuvant therapy. Identification of molecular markers to predict treatment outcome is therefore warranted. The aim of the present study was to evaluate whether expression of novel candidate biomarkers, including microRNAs, can predict clinical outcome in PDAC patients treated with adjuvant therapy.
Formalin-fixed paraffin embedded specimens from a cohort of 82 resected Korean PDAC cases were analyzed for protein expression by immunohistochemistry and for microRNA expression using quantitative Real-Time PCR. Cox proportional hazards model analysis in the subgroup of patients treated with adjuvant therapy (N = 52) showed that lower than median miR-21 expression was associated with a significantly lower hazard ratio (HR) for death (HR = 0.316; 95%CI = 0.166-0.600; P = 0.0004) and recurrence (HR = 0.521; 95%CI = 0.280-0.967; P = 0.04). MiR-21 expression status emerged as the single most predictive biomarker for treatment outcome among all 27 biological and 9 clinicopathological factors evaluated. No significant association was detected in patients not treated with adjuvant therapy. In an independent validation cohort of 45 frozen PDAC tissues from Italian cases, all treated with adjuvant therapy, lower than median miR-21 expression was confirmed to be correlated with longer overall as well as disease-free survival. Furthermore, transfection with anti-miR-21 enhanced the chemosensitivity of PDAC cells.
Low miR-21 expression was associated with benefit from adjuvant treatment in two independent cohorts of PDAC cases, and anti-miR-21 increased anticancer drug activity in vitro. These data provide evidence that miR-21 may allow stratification for adjuvant therapy, and represents a new potential target for therapy in PDAC.
Pancreatic cancer is an extremely aggressive disease; although progress has been made in the last few years, the prognosis of these patients remains dismal. FOLFIRINOX is now considered a standard ...treatment in first-line setting, since it demonstrated an improved overall and progression-free survival vs gemcitabine alone. However, the enthusiasm over the benefit of this three-drug regimen is tempered by the associated increased toxicity profile, and many efforts have been made to improve the feasibility of this schedule. After a more recent phase Ⅲ trial showing an improved outcome over gemcitabine, the combination of gemcitabine/nab-paclitaxel emerged as another standard first-line treatment. However, this treatment is also associated with more side effects. In addition, despite initial promising data on the predictive role of SPARClevels, recent studies showed that these levels are not associated with nab-paclitaxel efficacy. The choice to use this treatment over FOLFIRINOX is therefore a topic of debate, also because no validated biomarkers to guide FOLFIRINOX treatment are available. In the era of actionable mutations and target agents it would be desirable to identify molecular factors or biomarkers to predict response to therapy in order to maximize the efficacy of treatment and avoid useless toxic effects for non-responding patients. However, until today the milestone of treatment for pancreatic cancer remains chemotherapy combinations, without predictive or monitoring tools existing to optimize therapy. This review analyzes the state-of-the-art treatments, promises and limitations of targeted therapies, ongoing trials and future perspectives, including potential role of microR NAs as predictive biomarkers.
The energy metabolism of tumor cells is considered one of the hallmarks of cancer because it is different from normal cells and mainly consists of aerobic glycolysis, fatty acid oxidation, and ...glutaminolysis. It is about one hundred years ago since Warburg observed that cancer cells prefer aerobic glycolysis even in normoxic conditions, favoring their high proliferation rate. A pivotal enzyme driving this phenomenon is lactate dehydrogenase (LDH), and this review describes prognostic and therapeutic opportunities associated with this enzyme, focussing on tumors with limited therapeutic strategies and life expectancy (i.e., pancreatic and thoracic cancers). Expression levels of LDH-A in pancreatic cancer tissues correlate with clinicopathological features: LDH-A is overexpressed during pancreatic carcinogenesis and showed significantly higher expression in more aggressive tumors. Similarly, LDH levels are a marker of negative prognosis in patients with both adenocarcinoma or squamous cell lung carcinoma, as well as in malignant pleural mesothelioma. Additionally, serum LDH levels may play a key role in the clinical management of these diseases because they are associated with tissue damage induced by tumor burden. Lastly, we discuss the promising results of strategies targeting LDH as a treatment strategy, reporting recent preclinical and translational studies supporting the use of LDH-inhibitors in combinations with current/novel chemotherapeutics that can synergistically target the oxygenated cells present in the tumor.
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