Enhanced Anticancer Activity of 5’-DFUR-PCL-MPEG Polymeric Prodrug Micelles Encapsulating Chemotherapeutic Drugs

Abstract

The compound 5’-deoxy-5-fluorouridine (5’-DFUR) is a prodrug of the anti-tumor drug 5-fluorouracil (5-FU). Thymidine phosphorylase (TP) is an enzyme that can convert 5’-DFUR to its active form 5-FU and the expression of TP is upregulated in various cancer cells. In this study, 5’-DFUR associated with amphiphilic copolymer poly(ε-caprolactone)-methoxy poly(ethylene glycol) (5’-DFUR-PCL-MPEG) was synthesized, characterized, and self-assembled into functional polymeric micelles. To demonstrate that the prodrug 5’-DFUR could convert into cytotoxic 5-fluorouracil (5-FU) by endogenous TP, HT-29 colorectal cancer cells were treated with 5’-DFUR-PCL-MPEG polymeric micelles for various time periods. Chemotherapeutic drugs doxorubicin (DOX) and 7-ethyl-10-hydroxycamptothecin (SN-38) were also encapsulated separately into 5’-DFUR-PCL-MPEG polymeric micelles to create a dual drug-loaded system. HT-29 cells were treated with DOX or SN-38 encapsulated 5’-DFUR-PCL-MPEG polymeric micelles to examine the efficacy of dual drug-loaded micelles. As a result, HT-29 cells treated with 5’-DFUR-PCL-MPEG polymeric micelles showed up to 40% cell death rate after a 72-h treatment. In contrast, HT-29 cells challenged with DOX or SN-38 encapsulated 5’-DFUR-incorporated polymeric micelles showed 36% and 31% in cell viability after a 72-h treatment, respectively.

Efficient Expression of Soluble Recombinant Protein Fused with Core-Streptavidin in Bacterial Strain with T7 Expression System

“…Since 20 µL of purified fusion protein was used, the TP-coreSA enzyme activity was calculated to be 4.98 ± 0.13 µmole/µg/h. It should be noted that the enzyme activity obtained here is much higher than the reported values ranged from 0.269 to 3.383 µmole/mg/h [14,[16][17][18]. This is because the literature-reported values of TP enzyme activity were obtained by dividing total amount of crude protein; however, in this study, the enzyme activity of TP-coreSA was calculated by dividing the purified protein, hence, it is much higher than the values reported.…”

Polymeric Nanovectors Incorporated with Ganciclovir and HSV-tk Encoding Plasmid for Gene-Directed Enzyme Prodrug Therapy

“…It should be noted that the hydrophobic core of polymeric prodrug micelles was not loaded with any other anticancer drugs. It is foreseeable that, with the encapsulation of hydrophobic chemotherapy drug (e.g., into GCV-incorporated polymeric micelles, HT29 cells will have more death than the ones shown in Figure 12 due to the combination effect of both GCV and chemotherapy drug on HT29 cells expressing HSV-tk enzyme [40]. transported into the nucleus and resulted in the expression of GCV-activating HSV-tk enzyme that eventually converted GCV into toxic GCV-TP for malignant cell destruction (see Figure 1 for illustration).…”

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

“…The nal absorbance was measured again at 305 nm, and the amount 5-FU produced was calculated by using the calibration curve of 5-FU at 305 nm. 4,8 The calibration curve was obtained by plotting the measured absorbances of 5-FU serial dilutions against its concentrations. The TYMP enzyme activity was then calculated as the amount of 5-FU formed/mg protein per hour using the calibration curve and the concentration of puried protein obtained from the BCA protein assay.…”

“…Since then, it is approved for various cancer types such as for the treatment of breast, colon, and gastric cancers. 4,5 It is usually administrated through continuous infusion to patients because of the short plasma half-life. 6 However, to avoid the toxic effect, its prodrug such as capecitabine or doxiuridine (5 0 -DFUR) are used that are non-toxic.…”

“…7,8 Several studies have shown the efficacy of 5 0 -DFUR is linked with the expression and activity of TYMP in tumor sites. 4,9 The endogenous expression of TYMP in cancer cells is usually not enough to convert prodrug (5 0 -DFUR) into a toxic drug . The enhanced anti-cancer activity by non-toxic prodrug can be achieved by delivering TYMP on the cancer site to upregulate its expression level.…”