Mesenchymal stem cells anchored with thymidine phosphorylase for doxifluridine-mediated cancer therapy

Thymidine phosphorylase in nucleotide metabolism: physiological functions and its implications in tumorigenesis and anti-cancer therapy

Thymidine phosphorylase (TYMP), a protein found in both prokaryotic and eukaryotic cells, is encoded by a gene located in the q13 region of chromosome 22. With a relative molecular mass of 55,000, TYMP exists as a homodimer. Recent research has increasingly illuminated the diverse functions of TYMP. It is known to facilitate platelet activation, osteoclast differentiation, and angiogenesis. Mutations in the TYMP gene are linked to mitochondrial neurogastrointestinal encephalomyopathy. Beyond its physiological roles, TYMP contributes significantly to tumor growth and cancer progression, where it promotes angiogenesis, modulates epigenetic genes, inhibits apoptosis, and acts as a critical enzyme in the nucleoside metabolic rescue pathway. Moreover, TYMP holds substantial implications in cancer treatment and prognosis. Given its involvement in cancer progression, TYMP inhibitors may prove valuable in inhibiting tumor growth and metastasis. Interestingly, while TYMP can drive tumor growth, certain concentrations of TYMP also enhance the cytotoxic effects of chemotherapy drugs such as 5-fluorouracil (5-FU). Although challenges exist-such as the potential disruption of normal physiological functions when inhibiting TYMP-the protein remains a promising target for cancer treatment. Ongoing research on TYMP could deepen our understanding of human physiology and the pathogenesis of cancer and open new avenues for therapeutic interventions. This article provides a comprehensive review of TYMP's structure, physiological functions, and its role in tumorigenesis and anti-tumor therapy.

Proteomic profiling of gliomas unveils immune and metabolism-driven subtypes with implications for anti-nucleotide metabolism therapy

Gliomas exhibit high heterogeneity and poor prognosis. Despite substantial progress has been made at the genomic and transcriptomic levels, comprehensive proteomic characterization and its implications remain largely unexplored. In this study, we perform proteomic profiling of gliomas using 343 formalin-fixed and paraffin-embedded tumor samples and 53 normal-appearing brain samples from 188 patients, integrating these data with genomic panel information and clinical outcomes. The proteomic analysis uncovers two distinct subgroups: Subgroup 1, the metabolic neural subgroup, enriched in metabolic enzymes and neurotransmitter receptor proteins, and Subgroup 2, the immune subgroup, marked by upregulation of immune and inflammatory proteins. These proteomic subgroups show significant differences in prognosis, tumorigenesis, microenvironment dysregulation, and potential therapeutics, highlighting the critical roles of metabolic and immune processes in glioma biology and patient outcomes. Through a detailed investigation of metabolic pathways guided by our proteomic findings, dihydropyrimidine dehydrogenase (DPYD) and thymidine phosphorylase (TYMP) emerge as potential prognostic biomarkers linked to the reprogramming of nucleotide metabolism. Functional validation in patient-derived glioma stem cells and animal models highlights nucleotide metabolism as a promising therapy target for gliomas. This integrated multi-omics analysis introduces a proteomic classification for gliomas and identifies DPYD and TYMP as key metabolic biomarkers, offering insights into glioma pathogenesis and potential treatment strategies.

Design, Synthesis, and Evaluation of Doxifluridine Derivatives as Nitroreductase-Responsive Anticancer Prodrugs

Antimetabolite antitumor drugs interfere with nucleic acid and DNA synthesis, causing cancer cell death. However, they also affect rapidly dividing normal cells and cause serious side effects. Doxifluridine (5'-deoxy-5-fluorouridine [5'-DFUR]), a 5-fluorouracil (5-FU) prodrug converted to 5-FU by thymidine phosphorylase (TP), exerts antitumor effects. Since TP is distributed in tumor and normal tissues, 5'-DFUR features side effects. Here we designed a series of novel 5'-DFUR derivatives based on high nitroreductase (NTR) levels in the hypoxic microenvironment of tumor tissues by introducing nitro-containing moieties into the 5'-DFUR structure. These derivatives exert their antitumor effects by producing 5-FU under the dual action of TP and NTR in the tumor microenvironment. The derivatives were synthesized and their stability, release, and cytotoxicity evaluated in vitro and antitumor activity evaluated in vivo. Compound 2c, featuring nitrofuran fragments, was stable in phosphate-buffered saline and plasma at different pH values and reduced rapidly in the presence of NTR. The in vitro cytotoxicity evaluation indicated that compound 2c showed excellent selectivity in the MCF-7 and HT29 cell lines. Moreover, it exhibited antitumor effects comparable to those of 5'-DFUR in vivo without significant toxic side effects. These results suggest that compound 2c is a promising antitumor prodrug.

1,3,4-Oxadiazole: An Emerging Scaffold to Inhibit the Thymidine Phosphorylase as an Anticancer Agent

Thymidine phosphorylase (TP), also referred to as "platelet-derived endothelial cell growth factor" is crucial to the pyrimidine salvage pathway. TP reversibly transforms thymidine into thymine and 2-deoxy-D-ribose-1-phosphate (dRib-1-P), which further degraded to 2-Deoxy-D-ribose (2DDR), which has both angiogenic and chemotactic activity. In several types of human cancer such as breast and colorectal malignancies, TP is abundantly expressed in response to biological disturbances like hypoxia, acidosis, chemotherapy, and radiation therapy. TP overexpression is highly associated with angiogenic factors such as vascular endothelial growth factor (VEGF), interleukins (ILs), matrix metalloproteases (MMPs), etc., which accelerate tumorigenesis, invasion, metastasis, immune response evasion, and resistant to apoptosis. Hence, TP is recognized as a key target for the development of new anticancer drugs. Heterocycles are the primary structural element of most chemotherapeutics. Even 75% of nitrogen-containing heterocyclic compounds are contributing to the pharmaceutical world. To create the bioactive molecule, medicinal chemists are concentrating on nitrogen-containing heterocyclic compounds such as pyrrole, pyrrolidine, pyridine, imidazole, pyrimidines, pyrazole, indole, quinoline, oxadiazole, benzimidazole, etc. The Oxadiazole motif stands out among all of them due to its enormous significance in medicinal chemistry. The main thrust area of this review is to explore the synthesis, SAR, and the significant role of 1,3,4-oxadiazole derivatives as a TP inhibitor for their chemotherapeutic effects.

Eradication of Myrosinase-Tethered Cancer Cells by Allyl Isothiocyanate Derived from Enzymatic Hydrolysis of Sinigrin

Sinigrin is present in significant amounts in cruciferous vegetables. Epidemiological studies suggest that the consumption of such vegetables decreases the risk of cancer, and the effect is attributed mainly to allyl isothiocyanate (AITC), a hydrolysis product of sinigrin catalyzed by myrosinase. Anticancer activity of AITC has been previously investigated for several cancer models, but less attention was paid to delivering AITC on the target site. In this study, the gene sequences of core streptavidin (coreSA) and myrosinase (MYR) were cloned in a pET-30a(+) plasmid and transformed into BL21(DE3) E. coli competent cells. The MYR-coreSA chimeric protein was expressed and purified using immobilized metal affinity chromatography and further characterized by gel electrophoresis, Western blot, and enzyme activity assay. The purified MYR-coreSA chimeric protein was tethered on the outer membrane of biotinylated adenocarcinoma A549 cells and then treated with various concentrations of sinigrin. Our results showed that 20 µM of sinigrin inhibited the growth of A549 cells tethered with myrosinase by ~60% in 48 h. Furthermore, the levels of treated cells undertaken apoptosis were determined by Caspase-3/7 activation and Annexin-V. In summary, sinigrin harnessed like a prodrug catalyzed by myrosinase to the production of AITC, which induced cell apoptosis and arrested the growth of lung cancer cells.