Thymidine Phosphorylase Research Articles

Identifying TYMP as an Immune Prognostic Marker in Clear Cell Renal Cell Carcinoma.

In clear cell renal cell carcinoma (ccRCC), only some patients can benefit from immunotherapy therapy, and it is urgent to find immune-related molecular markers and targets. Thymidine phosphorylase (TYMP) expression level and predictive value in pan-cancers were analyzed using TIMER, GEPIA2, and The Human Protein Atlas. We obtained ccRCC tissues to verify the differential expression of TYMP and confirmed the biological function in vitro. Subsequently, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) are used to explore the potential mechanism of TYMP. Finally, TIMER was used to analyze the infiltration levels and prognostic value of different immune cells. TYMP is upregulated in various cancers, including ccRCC, and there is a certain degree of causality between high expression and poor prognosis in ccRCC. It was confirmed that TYMP knockdown could suppress cell aggressiveness, and cause cell death. Differential analysis showed that 55 differential genes were upregulated in the high-expression groups of TYMP. KEGG and GSEA analyses suggested that TYMP was linked to immune cell invasion, fatty acid metabolism, and P53 signaling pathway. Further investigation revealed that the expression level of TYMP linked positively to T-cell follicular helper and Tregs, but negatively with mast cell activation. Finally, a Nomogram was established on the base of expression level of TYMP and the clinical characteristics of ccRCC patients to predict prognosis. Patient survival is poor and immune cell infiltration is abnormal when TYMP is highly expressed in ccRCC, suggesting that ccRCC patients could benefit from using TYMP as a molecular diagnostic and therapeutic target.

МИТОХОНДРИАЛЬНАЯ НЕЙРОГАСТРОИНТЕСТИНАЛЬНАЯ ЭНЦЕФАЛОМИОПАТИЯ: КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ

A clinical case of mitochondrial neurogastrointestinal encephalopathy (MNGIE), a rare autosomal recessive multisystem disease caused by TYMP gene mutations and thymidine phosphorylase (TP) deficiency, is presented. Authors draw the specialists’ attention to the complexity of making a diagnosis and the importance of an interdisciplinary approach in the diagnosis and management of such patients with the purpose of increasing the pediatric practitioners’ MNGIE awareness thereby reducing the time to diagnosis, which in its turn improves the prognosis for the course of the disease for the patients.

Bioinformatics analysis identified RGS4 as a potential tumor promoter in glioma.

Gliomas is the most common type of intracranial primary malignant tumor and it accounts for ∼80% of primary malignant tumors of the central nervous system. At present, surgical resection with adjuvant radiotherapy and temozolomide adjuvant chemotherapy combined with radiotherapy are the only standard treatments for glioma. However, but overall survival of patients is only 15 months. Glioma is resistant to radiotherapy and chemotherapy, and this malignant behavior leads to a high recurrence rate. Therefore, the use of therapeutics is usually ineffective. As a result, patients with glioma do not significantly benefit from standard treatment. There is therefore an urgent need to develop novel diagnostic approaches and, in particular, more effective treatment strategies. The application of gene expression microarrays provides a feasible and effective way to study gliomas. The present study therefore aimed to identify the key protein-coding genes of glioma using bioinformatics methods and thereby search, for novel biomarkers and therapeutic targets for the treatment of glioma. First, mRNA microarray datasets were selected and obtained from the Gene Expression Omnibus database to identify differentially expressed genes (DEGs) between gliomas and normal tissues. The DEGs were clarified using Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), Protein-Protein Interaction (PPI) network and statistical analysis. Subsequently, reverse transcription-quantitative PCR (RT-qPCR)and western blot were used to verify the results of the bioinformatics analysis. A total of 400 DEGs were identified in glioma and they were enriched in several cancer-related GO and KEGG pathways. In the PPI network, it was observed that G-protein signal regulatory protein 4 (RGS4), thymidine phosphorylase, collagen type VI alpha-1, Src homology 2 domain-containing transforming protein1(SHC1) and ring finger protein 135 exhibited a strong protein-protein interaction. Furthermore, . Subsequently, brain damaged tissues and glioma cell lines were selected for RT-qPCR and western blotting analysis. The results demonstrated that RGS4 was highly expressed in glioma cell lines. In conclusion, RGS4 may be a key protein-coding gene in glioma. RGS4 should therefore be studied further to verify its feasibility and effectiveness as a potential glioma biomarker and therapeutic target.

Capecitabine induces hand-foot syndrome through elevated thymidine phosphorylase-mediated locoregional toxicity and GSDME-driven pyroptosis that can be relieved by tipiracil.

Hand-foot syndrome (HFS) is a serious dose-limiting cutaneous toxicity of capecitabine-containing chemotherapy, leading to a deteriorated quality of life and negative impacts on chemotherapy treatment. The symptoms of HFS have been widely reported, but the precise molecular and cellular mechanisms remain unknown. The metabolic enzyme of capecitabine, thymidine phosphorylase (TP) may be related to HFS. Here, we investigated whether TP contributes to the HFS and the molecular basis of cellular toxicity of capecitabine. TP-/- mice were generated to assess the relevance of TP and HFS. Cellular toxicity and signalling mechanisms were assessed by in vitro and in vivo experiments. TP-/- significantly reduced capecitabine-induced HFS, indicating that the activity of TP plays a critical role in the development of HFS. Further investigations into the cellular mechanisms revealed that the cytotoxicity of the active metabolite of capecitabine, 5-DFUR, was attributed to the cleavage of GSDME-mediated pyroptosis. Finally, we demonstrated that capecitabine-induced HFS could be reversed by local application of the TP inhibitor tipiracil. Our findings reveal that the presence of elevated TP expression in the palm and sole aggravates local cell cytotoxicity, further explaining the molecular basis underlying 5-DFUR-induced cellular toxicity and providing a promising approach to the therapeutic management of HFS.

Mitochondrial neurogastrointestinal encephalomyopathy in a Pakistani female: a case report

BackgroundMitochondrial neurogastrointestinal encephalopathy is a rare multisystem autosomal recessive disease caused by mutations in the TYMP gene, that encodes for thymidine phosphorylase. Mitochondrial neurogastrointestinal encephalopathy is a progressive degenerative disease characterized by a distinctive tetrad of gastrointestinal dysmotility, peripheral neuropathy, ophthalmoplegia with ptosis, and asymptomatic leukoencephalopathy. It provides a diagnostic dilemma to physicians in regions like Pakistan because of a lack of genetic study availability and associated financial constraints of the population. However, with careful examination and a few basic investigations, mitochondrial neurogastrointestinal encephalopathy can be diagnosed by ruling out most of the close differentials.Case presentationWe report the case of a 23-year-old Asian female whose chief complaints were epigastric pain, bilious emesis, weight loss for 3 months, and bilateral lower limb weakness for 20 days. All clinical signs and symptoms along with relevant investigations including nerve conduction studies, electromyography, and magnetic resonance imaging of the brain were highly suggestive of mitochondrial neurogastrointestinal encephalopathy syndrome. Because of financial constraints, genetic studies could not be performed. The patient was managed with a multidisciplinary approach involving gastroenterology, physiotherapy, and nutrition departments. Currently, therapeutic options for the disease include allogeneic hematopoietic stem cell transplant and carrier erythrocyte entrapped thymidine phosphorylase; however, these could not be provided to the patient owing to certain limitations.ConclusionsAs misdiagnosis and delayed diagnosis are quite common in this disease, the prime objective of this case report is to increase the basic understanding of this disease, especially its signs and symptoms, and address the limitations regarding the diagnostic investigations and management of patients with mitochondrial neurogastrointestinal encephalopathy.

Capecitabine-A "Permanent Mission" in Head and Neck Cancers "War Council"?

Capecitabine, an oral pro-drug that is metabolized to 5-FU, has been used in clinical practice for more than 20 years, being part of the therapeutic standard for digestive and breast cancers. The use of capecitabine has been evaluated in many trials including cases diagnosed in recurrent or metastatic settings. Induction regimens or a combination with radiation therapy were evaluated in head and neck cancers, but 5-FU still remained the fluoropyrimidine used as a part of the current therapeutic standard. Quantifications of levels or ratios for enzymes are involved in the capecitabine metabolism to 5-FU but are also involved in its conversion and elimination that may lead to discontinuation, dose reduction or escalation of treatment in order to obtain the best therapeutic ratio. These strategies based on biomarkers may be relevant in the context of the implementation of precision oncology. In particular for head and neck cancers, the identification of biomarkers to select possible cases of severe toxicity requiring discontinuation of treatment, including “multi-omics” approaches, evaluate not only serological biomarkers, but also miRNAs, imaging and radiomics which will ensure capecitabine a role in both induction and concomitant or even adjuvant and palliative settings. An approach including routine testing of dihydropyrimidine dehydrogenase (DPD) or even the thymidine phosphorylase (TP)/DPD ratio and the inclusion of miRNAs, imaging and radiomics parameters in multi-omics models will help implement “precision chemotherapy” in HNC, a concept supported by the importance of avoiding interruptions or treatment delays in this type of cancer. The chemosensitivity and prognostic features of HPV-OPC cancers open new horizons for the use of capecitabine in heavily pretreated metastatic cases. Vorinostat and lapatinib are agents that can be associated with capecitabine in future clinical trials to increase the therapeutic ratio.

Pulmonary Thrombosis Promotes Tumorigenesis via Myeloid Hypoxia-Inducible Factors

Cancer patients have a greater risk of thrombosis than individuals without cancer. Conversely, thrombosis is a diagnostic predictor of cancer, but the mechanisms by which thrombosis promotes tumor propagation are incompletely understood. Our previous studies showed that hypoxia-inducible factors (HIF) 1α and HIF2α are stabilized in myeloid cells of murine thrombi. We also previously showed that pulmonary thrombosis increases the levels of HIF1α and HIF2α in murine lungs, enhances the levels of tumorigenic factors in the circulation, and promotes pulmonary tumorigenesis. In this study, we aimed to investigate the regulation of thrombosis-induced tumorigenesis by myeloid cell-specific HIFs (i.e., HIF1 and HIF2 in neutrophils and macrophages). Our in vitro studies showed that multiple tumorigenic factors are upregulated in the secretome of hypoxic versus normoxic neutrophils and macrophages, which promotes lung cancer cell proliferation and migration in a myeloid-HIF-dependent manner. Next, we used a mouse model of pulmonary microvascular occlusion to study the impact of pulmonary thrombosis and myeloid HIFs on lung tumorigenesis. Experiments on mice lacking either HIF1α or HIF2α in myeloid cells demonstrated that loss of either factor eliminates the advantage given to pulmonary tumor formation by thrombotic insult. The myeloid HIF-dependent and tumorigenic impact of pulmonary thrombosis on tumor burden may be partly driven by paracrine thymidine phosphorylase (TP), given that TP levels were increased by hypoxia in neutrophil and macrophage supernates, and that plasma TP levels were positively correlated with multiple measures of tumor progression in wild type mice but not myeloid cell-specific HIF1α or HIF2α knockout mice. These data together demonstrate the importance of thrombotic insult in a model of pulmonary tumorigenesis and the essential role of myeloid HIFs in mediating tumorigenic success.

Combination of T cell-redirecting bispecific antibody ERY974 and chemotherapy reciprocally enhances efficacy against non-inflamed tumours

Identifying a strategy with strong efficacy against non-inflamed tumours is vital in cancer immune therapy. ERY974 is a humanized IgG4 bispecific T cell-redirecting antibody that recognizes glypican-3 and CD3. Here we examine the combination effect of ERY974 and chemotherapy (paclitaxel, cisplatin, and capecitabine) in the treatment of non-inflamed tumours in a xenograft model. ERY974 monotherapy shows a minor antitumour effect on non-inflamed NCI-H446 xenografted tumours, as infiltration of ERY974-redirected T cells is limited to the tumour-stromal boundary. However, combination therapy improves efficacy by promoting T cell infiltration into the tumour centre, and increasing ERY974 distribution in the tumour. ERY974 increases capecitabine-induced cytotoxicity by promoting capecitabine conversion to its active form by inducing thymidine phosphorylase expression in non-inflamed MKN45 tumour through ERY974-induced IFNγ and TNFα in T cells. We show that ERY974 with chemotherapy synergistically and reciprocally increases antitumour efficacy, eradicating non-inflamed tumours.

Synthesis, reaction, antimicrobial, and docking study of new chalcones incorporating isoquinoline moiety

Reaction of isoquinoline 1 with hydrazonoyl chlorides 2A–E gave the corresponding triazoloisoquinolines 4A–E. The latter products 4A–E were reacted with 4-(piperidin-1-yl)benzaldehyde 5a and 4-morpholinobenzaldehyde 5b to afford the corresponding chalcones 6a,b. Some of chalcones 6 were reacted with hydrazine hydrate in refluxing ethanol to give the corresponding 8,9-dimethoxy-1-aryl-4,5-dihydro-1H-pyrazol-3-yl-1,5,6,10b-tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline derivatives 7A–C. Antimicrobial studies were performed using gram-negative bacteria (Escherichia coli) and (Klebsiella pneumonia), a gram-positive bacteria (Streptococcus mutans) and (Staphylococcus aureus), filamentous fungus (Asperagillus Nigar) and yeast (Candida albicans). Data revealed that chalcone 6Aa achieved the lowest MIC values (high efficient derivative) against the sensitive bacterial strain E. coli with MIC value 130 µg/ml. The most effective compound 6Aa, which demonstrated the highest binding affinity toward tested protein [thymidine phosphorylase enzyme, (PDB ID:4EAD)], was docked using MOE 2014.09 software.

Targeting thymidine phosphorylase alleviates resistance to dendritic cell immunotherapy in colorectal cancer and promotes antitumor immunity.

T-cell exhaustion plays a pivotal role in the resistance of microsatellite-stable colorectal cancer (CRC) to immunotherapy. Identifying and targeting T-cell exhaustion-activating mechanisms is a promising strategy to augment the effects of immunotherapy. Here, we found that thymidine phosphorylase (TYMP) plays a decisive role in inducing systemic T-cell exhaustion and abrogating the efficacy of dendritic cell (DC) therapy in a CRC model. Targeting TYMP with tipiracil hydrochloride (TPI) induces immunological cell death (ICD). The combined effects of TPI and imiquimod-activated DCs turn CT26 tumors into immunologically ‘hot’ tumors by inducing ICD in vivo. High-dimensional cytometry analysis revealed T-cell and IFN-γ dependency on the therapeutic outcome. In addition, chemoimmunotherapy converts intratumoral Treg cells into Th1 effector cells and eliminates tumor-associated macrophages, resulting in higher cytotoxic T lymphocyte infiltration and activation. This effect is also associated with the downregulation of PD-L1 expression in tumors, leading to the prevention of T-cell exhaustion. Thus, cooperative and cognitive interactions between dendritic cells and immunogenic cell death induced by therapy with TPI promote the immune response and tumoricidal activities against microsatellite stable colorectal cancer. Our results support TYMP targeting to improve the effects of DC immunotherapy and outcomes in CRC.

Ginseng-derived nanoparticles inhibit lung cancer cell epithelial mesenchymal transition by repressing pentose phosphate pathway activity.

It is unclear whether ginseng-derived nanoparticles (GDNPs) can prevent tumor cell epithelial-mesenchymal transition (EMT). Here, we describe typical characteristics of GDNPs and possible underlying mechanisms for GDNP antitumor activities. First, GDNPs particle sizes and morphology were determined using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM), respectively, while cellular uptake of PKH67-labeled GDNPs was also assessed. Next, we evaluated GDNPs antitumor effects by determining whether GDNPs inhibited proliferation and migration of five tumor cell lines derived from different cell types. The results indicated that GDNPs most significantly inhibited proliferation and migration of lung cancer-derived tumor cells (A549, NCI-H1299). Moreover, GDNPs treatment also inhibited cell migration, invasion, clonal formation, and adhesion tube formation ability and reduced expression of EMT-related markers in A549 and NCI-H1299 cells in a dose-dependent manner. Meanwhile, Kaplan-Meier analysis of microarray data revealed that high-level thymidine phosphorylase (TP) production, which is associated with poor lung cancer prognosis, was inhibited by GDNPs treatment, as reflected by decreased secretion of overexpressed TP and downregulation of TP mRNA-level expression. In addition, proteomic analysis results indicated that GDNPs affected pentose phosphate pathway (PPP) activity, with ELISA results confirming that GDNPs significantly reduced levels of PPP metabolic intermediates. Results of this study also demonstrated that GDNPs-induced downregulation of TP expression led to PPP pathway inhibition and repression of lung cancer cell metastasis, warranting further studies of nano-drugs as a new and promising class of anti-cancer drugs.

Heat shock protein 90 inhibitor 17-AAG down-regulates thymidine phosphorylase expression and potentiates the cytotoxic effect of tamoxifen and erlotinib in human lung squamous carcinoma cells

Elevated thymidine phosphorylase (TP) levels, a key enzyme in the pyrimidine nucleoside salvage pathway, in cancer cells, are related to a poor prognosis in a variety of cancers. Heat shock protein 90 (Hsp90) is a ubiquitous molecular chaperone that is involved in the stabilization and maturation of many oncogenic proteins. The aim of this study is to elucidate whether Hsp90 inhibitor 17-AAG could enhance tamoxifen- and erlotinib-induced cytotoxicity in nonsmall cell lung cancer (NSCLC) cells via modulating TP expression in two squamous NSCLC cell lines, H520 and H1703. We found that 17-AAG reduced TP expression via inactivating the MKK1/2-ERK1/2-mitogen-activated protein kinase (MAPK) pathway. TP knockdown with siRNA or ERK1/2 MAPK inactivation with the pharmacological inhibitor U0126 could enhance the cytotoxic and growth inhibitory effects of 17-AAG. In contrast, MKK1-CA or MKK2-CA (a constitutively active form of MKK1/2) vector-enforced expression could reduce the cytotoxic and cell growth inhibitory effects of 17-AAG. Furthermore, 17-AAG enhanced the cytotoxic and cell growth inhibitory effects of tamoxifen and erlotinib in NSCLC cells, which were associated with TP expression downregulation and MKK1/2-ERK1/2 signal inactivation. Taken together, Hsp90 inhibition downregulates TP, enhancing the tamoxifen- and erlotinib-induced cytotoxicity in H520 and H1703 cells.

Anatomical Laser Microdissection of the Ileum Reveals mtDNA Depletion Recovery in A Mitochondrial Neuro-Gastrointestinal Encephalomyopathy (MNGIE) Patient Receiving Liver Transplant.

mitochondrial neuro-gastrointestinal encephalomyopathy (MNGIE) is a rare genetic disorder characterized by thymidine phosphorylase (TP) enzyme defect. The absence of TP activity induces the imbalance of mitochondrial nucleotide pool, leading to impaired mitochondrial DNA (mtDNA) replication and depletion. Since mtDNA is required to ensure oxidative phosphorylation, metabolically active tissues may not achieve sufficient energy production. The only effective life-saving approach in MNGIE has been the permanent replacement of TP via allogeneic hematopoietic stem cell or liver transplantation. However, the follow-up of transplanted patients showed that gut tissue changes do not revert and fatal complications, such as massive gastrointestinal bleeding, can occur. The purpose of this study was to clarify whether the reintroduction of TP after transplant can recover mtDNA copy number in a normal range. Using laser capture microdissection and droplet-digital-PCR, we assessed the mtDNA copy number in each layer of full-thickness ileal samples of a naive MNGIE cohort vs. controls and in a patient pre- and post-TP replacement. The treatment led to a significant recovery of gut tissue mtDNA amount, thus showing its efficacy. Our results indicate that a timely TP replacement is needed to maximize therapeutic success before irreversible degenerative tissue changes occur in MNGIE.

The features of enzymes activity to nucleoside and antioxidant systems in solid tumors

Background. Solid tumors can create their aggressive properties. There are characterized by the invasion and metastatic activity, the resistance of the tumor clone to apoptosis. These pathways triggering may be realized both by 2-deoxy-D-ribose and its phosphorylated form (2-d-D-Rib-1-P), and by hydrogen peroxide.Aim. To investigate the peculiarities of enzymes activity to nucleoside metabolism and antioxidant system in epithelial tumors of different localization.Materials and methods. The features of the thymidine phosphorylase, adenosine deaminase, superoxide dismutase (SOD) and glutathione peroxidase (GPO) activity were studied in tumor homogenates. The visually no transformed tissues of the surgical resection edges were used as a control. Enzymes activity was determined by spectrophotometrical and morphological features were examined by the immunohistochemical methods in tissues of non-small cell lung cancer (NSCLC), samples of gastric and colon carcinomas (GCC).Results. Thymidine phosphorylase activity and adenosine deaminase activity in various malignant tumors were increased in comparison to the control. Respectively, thymidine phosphorylase activity was higher than by 1.8 times (p= 0.002 for NSCLC,p= 0.001 for GCC). An increase of adenosine deaminase activity was revealed both in tissues of NSCLC (more than 1.7 times) and in GCC (by 1.9 times,p= 0.001). No significant changes in SOD activity were detected in the tumors. GPO activity tended to decrease by an average of 1.3 times (p= 0.01 for NSCLC,p= 0.02 for GCC). A cluster analysis of the enzymatic activity features of the studied NSCLC tumors, as well as GCC, revealed their metabolic heterogeneity. According to its results, tumors of different localization were distinguished into 2 clusters. Common feature to their second clusters was an increase the SOD activity. It was accompanied by increase of thymidine phosphorylase activity (p= 0.045 for NSCLC,p= 0.049 for GCC). Therefore, both hydrogen peroxide and 2-d-D-Rib-1-P could be formed in them more intensively. It is important to note that morphological indicators of tumor aggression (decreased or lost expression of cell-cell adhesion marker, expression of mesenchymal markers, active angiogenesis) were detected more frequently in these subgroups.Conclusion. The obtained results reveal that individual features of the enzymes activity in epithelial tumors may be available source of 2-d-D-Rib-1-P and hydrogen peroxide generation in human cancer cells. In the case of individual higher tumor activity of thymidine phosphorylase and SOD and low GPO activity the metabolic stimulation of tumor progression may be occur.

The mechanism underlying resistance to 5-fluorouracil and its reversal by the inhibition of thymidine phosphorylase in breast cancer cells.

Fluoro-deoxyuridine monophosphate (FdUMP) is an active metabolite of 5-fluorouracil (5-FU) synthesized through two hypothesized pathways: The orotate phosphoribosyl transferase-ribonucleotide reductase (OPRT-RR) pathway and the thymidine phosphorylase-thymidine kinase (TP-TK) pathway. In the present study, the mechanism underlying 5-FU resistance was investigated, focusing on changes in 5-FU metabolism using MCF-7, 5-FU-resistant MCF-7/5-FUR, MDA-MB-231 and 5-FU-resistant MDA-MB-231/5-FUR breast cancer cells. The amount of FdUMP present following treatment with 5-FU was determined by the density of the upper band of thymidylate synthase detected by western blotting, and its changes were investigated. MCF-7/5-FUR cells exhibited 5-FU resistance (36.6-fold), and showed decreased OPRT (-69.3%) and TK (-42.6%) levels. MDA-MB-231/5-FUR cells also exhibited 5-FU resistance (15.8-fold), and showed decreased TP (-79.0%) and increased TK (+184%) levels. MCF-7/5-FUR and MDA-MB-231/5-FUR cells both showed decreased synthesis of FdUMP by 91 and 86%, respectively. In MCF-7 and MCF-7/5-FUR cells, the synthesis of FdUMP was decreased when 5-FU was combined with an RR inhibitor, indicating that FdUMP was synthesized through the OPRT-RR pathway. The synthesis of FdUMP was decreased when 5-FU was combined with a TP inhibitor in MDA-MB-231 cells and combined with an RR inhibitor in MDA-MB-231/5-FUR cells, indicating that the synthesis pathway of FdUMP was changed from the TP-TK pathway to the OPRT-RR pathway on acquiring resistance to 5-FU. Notably, the synthesis of FdUMP was increased and the resistance to 5-FU was reversed in MCF-7/5-FUR cells (half maximal inhibitory concentration (IC50): 219.9 to 0.093 µM) and MDA-MB-231/5-FUR cells (IC50: 157.3 to 31.0 µM) when 5-FU was combined with a TP inhibitor. In conclusion, the metabolism of 5-FU and the mechanism underlying the resistance to 5-FU differed among cell lines, and inhibition of TP reversed resistance to 5-FU, thus suggesting that the combination of 5-FU and a TP inhibitor may be considered a promising cancer therapy.

Osteocyte CIITA aggravates osteolytic bone lesions in myeloma

Osteolytic destruction is a hallmark of multiple myeloma, resulting from activation of osteoclast-mediated bone resorption and reduction of osteoblast-mediated bone formation. However, the molecular mechanisms underlying the differentiation and activity of osteoclasts and osteoblasts within a myelomatous microenvironment remain unclear. Here, we demonstrate that the osteocyte-expressed major histocompatibility complex class II transactivator (CIITA) contributes to myeloma-induced bone lesions. CIITA upregulates the secretion of osteolytic cytokines from osteocytes through acetylation at histone 3 lysine 14 in the promoter of TNFSF11 (encoding RANKL) and SOST (encoding sclerostin), leading to enhanced osteoclastogenesis and decreased osteoblastogenesis. In turn, myeloma cell–secreted 2-deoxy-D-ribose, the product of thymidine catalyzed by the function of thymidine phosphorylase, upregulates CIITA expression in osteocytes through the STAT1/IRF1 signaling pathway. Our work thus broadens the understanding of myeloma-induced osteolysis and indicates a potential strategy for disrupting tumor-osteocyte interaction to prevent or treat patients with myeloma bone disease.

P-50 RETRO-TAS, a retrospective observational study of rifluridine/tipiracil in chemorefractory metastatic colorectal cancer

Trifluridine/tipiracil (TAS-102) is an oral combination of an antineoplastic thymidine-based nucleoside analogue, trifluridine, and the thymidine phosphorylase (TPase) inhibitor, tipiracil hydrochloride, indicated for patients (pts) with metastatic colorectal cancer (mCRC) as third line therapy. The approved dose of TAS-102 in adults is 35 mg/m2/dose administered orally twice daily on Days 1 to 5 and Days 8 to 12 of each 28-day cycle as long as benefit is observed or until unacceptable toxicity occurs.

QSAR Applied to 4-Chloro-3-formylcoumarin Derivatives Targeting Human Thymidine Phosphorylase

Coumarins are secondary metabolites from the phenylpropanoid-type biosynthesis in higher plants. A plethora of potential phytopharmacological activities have been described for derivatives of the coumarin scaffold: hepatoprotective, antineoplastic, antimicrobial, antituberculosis, antiviral, anti-inflammatory anticoagulant, or antithrombotic effects. A computer-based quantitative structure – activity relationships (QSAR) study for a series of 4‑chloro-3-formylcoumarins was carried out. To this end we generated the 3D models of 17 published coumarin structures, calculated their physicochemical properties (descriptors) to correlate them to their experimentally known biological activities measured as inhibition concentrations to block the target enzyme activity. Our proposed approach used free molecular modeling software and applies our scripts written in the programming language R. The final multiple regression models achieved satisfactory results with a small number of descriptors – all of which were statistically significant and meaningful in the field of pharmacodynamics to develop new 3-formylcoumarins with enhanced activities targeting the human thymidine phosphorylase enzyme. On theoretical grounds, our in silico research contributes in a crucial step in the field of complementary phyto-medicine. This step is located between in vivo pharmacological observations of plant extracts on ethnopharmacological, preclinical or controlled clinical levels and the need to identify – at an atomic scale – all those plant ingredients responsible for the biological actions under scrutiny. Our simulations shed light on the modification of phyto-medicine’s physicochemical properties to enhance the interaction with their biomolecular target in the patient's body.

Study protocol of an open-label, single-arm, phase II trial investigating the efficacy and safety of trifluridine/tipiracil combined with irinotecan as a second-line therapy in patients with cholangiocarcinoma (TRITICC).

TPS4176 Background: Biliary tract cancers (BTC) currently account for ̃15% of all primary liver cancers and ̃3% of gastrointestinal malignancies. Gemcitabine/Cisplatin has been the standard of care in the first-line therapy of BTC for a decade. Despite recently some survival benefit has been shown in adding a checkpoint inhibitor, further lines of treatment are only poorly defined. In the ABC-06 phase-3 study, second-line FOLFOX demonstrated a moderate but significant improvement of survival and might be regarded as a standard of care. The combination of liposomal Irinotecan and 5-FU infusion pump also improved survival after first line therapy. Both mentioned second-line regimens are based on limited evidence and questionable generalizability. Thus, there is a high need for novel treatment concepts in patients without targetable genetic alterations. Trifluridine/tipiracil (FTD/TPI) is a orally active, antimetabolite agent comprised of trifluridine, a thymidine-based nucleoside analogue, and tipiracil, a potent thymidine phosphorylase inhibitor. Recent reports provided evidence of an antitumor activity of FTD/TPI plus Irinotecan as well in patients with BTC. Therefore, the TRITICC trial was designed to evaluate the safety and efficacy of FTD/TPI plus irinotecan in patients with BTC refractory to previous Gemcitabine based treatment. Methods: TRITICC (NCT04059562) is an interventional, prospective, open-label, non-randomized, exploratory, multicenter, single-arm phase IIA clinical trial that evaluates the safety and efficacy of FTD/TPI (25 mg/m² body surface area (BSA), BID, orally on days 1-5 followed by a 9-days recovery period from day 6 trough day 14 of each 14-days treatment cycle) plus irinotecan (on day 1 of each cycle at a dose of 180 mg/m2) in adult patients with histologically verified locally advanced or metastatic BTC (including cholangiocarcinoma and gallbladder or ampullary carcinoma) with documented radiological disease progression to first-line gemcitabine based chemotherapy. A total of 28 patients is planned to be enrolled in 6 sites across Germany. Study treatment will be continued until disease progression according to RECIST 1.1 criteria or occurrence of unacceptable toxicity. The effect of FTD/TPI plus irinotecan on progression-free survival will be analyzed as primary endpoint. Safety (according to NCI-CTCAE), response rates and overall survival are secondary endpoints. In addition, a comprehensive translational research program is part of the study and might provide findings about predictive markers with regard to response, survival periods and resistance to treatment. Currently, 3 out of the planned 6 German study sites are opened for recruitment and 6 patients have been enrolled. The primary study endpoint is estimated to be evaluated in 2023. Clinical trial information: NCT04059562.

Selective transportation and energy homeostasis regulation of dietary advanced glycation end-products in human intestinal Caco-2 cells

Advanced glycation end-products (AGEs) are a chemically heterogeneous set of modifications widely found in processed foods. Due to uncertain bioavailability, dietary AGEs regulate energy homeostasis through mechanisms that largely remain unclear. In this study, selective transmembrane transport of AGEs with different modification types from glycated β-casein digest were identified and compared. The results showed that only a few types of free and peptide-bound AGEs can easily cross the Caco-2 monolayers and thus exert their effects. A combination of biochemical assays, mitochondrial analyses, and comparative experiments identified that the effect of AGEs on cellular energy homeostasis comes mainly from their free fractions. Mechanistically, free AGEs arrest the mitochondrial differentiation and mtDNA repair by intervening in the function of thymidine phosphorylase, and interfering with mitochondrial energy production by inhibiting the activation of AMPK-SIRT6 signaling pathway. These results demonstrate mechanisms by which processed foods cause mitochondrial dysfunction and lead to dysfunctional energy homeostasis.