homologous nucleoside antibiotic; N-linked glycosylation; GlcNAc phosphotransferase (GPT)

In CD44+/CD24- and primary MCF7 cells, tunitamycin (2 μg/mL; 24 hours) treatment enhanced fragment-associated XBP-1, ATF6 nuclear translocation levels, and CHOP protein expression [1]. The findings demonstrate that CD44+/CD24- and CD44+/CD24-rich MCF7 cell cultures exhibit the following effects of tunicamycin: they decrease migration, increase cell death, and block migration [1].

In a CD133+/- MHCC97L cell xenograft model (BALB/c (nu/nu) mice), tunitoxin (0.1 mg/kg or 0.5 mg/kg) therapy greatly reduces tumor growth [2].

Western Blot Analysis
Cell Types: CD44+/CD24- and Original MCF7 Cells[1]
Tested Concentrations: 2 µg/mL
Incubation Duration: 24 hrs (hours)
Experimental Results: Spliced XBP-1, ATF6 nuclear transfer detected in CD44+/CD24- and original MCF7 cells and CHOP protein expression levels increased.

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Hepatocellular carcinoma is chemoresistant to many anticancer drugs. Tunicamycin, an N-glycosylation inhibitor, causes unfolded protein response and is widely used as pharmacological inducer of endoplasmic reticulum stress. In this study, several designs were used to investigate the resistance mechanism to camptothecin and etoposide in hepatocellular carcinoma Hep3B cells. Tunicamycin significantly inhibited apoptosis induced by camptothecin or etoposide. Tunicamycin neither modified the topoisomerase levels nor inhibited the ATM activation caused by camptothecin and etoposide. The data suggest that tunicamycin-induced resistance may result from the downstream events of drug-trapped topoisomerase-DNA complexes and DNA double-strand breaks. Camptothecin and etoposide caused an increase of protein expression of several cell-cycle regulators and induced the cleavage of Bcl-2 family of proteins. These intracellular molecular events were abolished by tunicamycin. A design of postaddition of tunicamycin demonstrated that G1 checkpoint arrest contributed to the resistance mechanism. Curcumin, another G1 arrest-inducing agent in this study, was able to induce a similar resistant effect. Furthermore, the cells transfected with GRP78 siRNA were partly resistant to tunicamycin-induced apoptosis but not the inhibitory effect on cell-cycle regulators indicating that GRP78 and G1 arrest are two independent factors to tunicamycin-induced resistance mechanism. In conclusion, the data suggest that tunicamycin induces the resistance to topoisomerase inhibitors through GRP78 up-regulation and G1 arrest of the cell cycle. The findings also prompt the deliberation that the resistance can be caused during combined administration of chemotherapeutic drugs and Chinese herbal medicines, which induce endoplasmic reticulum stress and/or cell-cycle arrest in cancer cells.[1]

Six- to 8-week-old BALB/c (nu/nu) mice were maintained under standard conditions according to protocols developed by the Shanghai Medical Experimental Animal Care Commission. At the end of the experimental period, the mice were euthanized, and the excised tumors were weighed and fixed in formalin. Frozen tumor samples were analyzed by Western blotting and real-time PCR. Details can be found in the Supplementary Data.[2]

[1]. Tunicamycin induces resistance to camptothecin and etoposide in human hepatocellular carcinoma cells: role of cell-cycle arrest and GRP78. Naunyn Schmiedebergs Arch Pharmacol. 2009 Nov;380(5):373-82.

[2]. DPAGT1/Akt/ABCG2 pathway in mouse Xenograft models of human hepatocellular carcinoma. Mol Cancer Ther. 2013 Dec;12(12):2874-84.

[3]. Endoplasmic reticulum stress inhibits cell cycle progression via induction of p27 in melanoma cells. Cell Signal. 2013 Jan;25(1):144-9.

[4]. Mechanisms associated with biogenesis of exosomes in cancer. Mol Cancer. 2019 Mar 30;18(1):52.

Hepatocellular carcinoma is highly chemoresistant, and ATP-binding cassette subfamily G member 2 (ABCG2) is thought to play a critical role in this drug resistance. The present study aims to develop effective therapeutic strategies to decrease ABCG2 expression level and to surmount drug resistance in hepatocellular carcinoma chemotherapy. First, we verified a positive correlation between the ABCG2 protein level and the drug resistance of hepatocellular carcinoma cell lines. ABCG2 was preferentially expressed in highly chemoresistant hepatocellular carcinoma cancer stem cells (CSC) enriched with CD133. In addition, ABCG2 was N-linked glycosylated in hepatocellular carcinoma cells, and this modification was involved in sustaining its protein stability. The N-linked glycosylation (NLG) inhibitor tunicamycin dramatically reduced ABCG2 expression, altered its subcellular localization, and reversed its drug efflux effect in multiple hepatocellular carcinoma cell lines. Furthermore, tunicamycin reduced the expression levels of several CSC markers and suppressed the tumorigenicity of CD133(+) CSCs. Tunicamycin combined with cisplatin (CDDP) inhibited proliferating cell nuclear antigen (PCNA) expression and increased the cleavage of PARP; this effect was partially rescued by the overexpression of ABCG2 or Akt-myr. The combination therapy more effectively suppressed tumor growth in xenograft mice than did single-agent therapy with either drug. Finally, the CDDP treatment combined with UDP-GlcNAc-dolichol-phosphate N-acetylglucosamine-1 phosphate transferase (DPAGT1) knockdown recapitulated the effect observed when CDDP was used in combination with tunicamycin. In summary, our results suggest that tunicamycin may reverse the drug resistance and improve the efficacy of combination treatments for hepatocellular carcinomas by targeting the DPAGT1/Akt/ABCG2 pathway[2].

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The accumulation of unfolded proteins in the endoplasmic reticulum (ER) triggers the unfolded protein response (UPR), a stress signaling pathway. The UPR coordinates the induction of ER chaperones with decreased protein synthesis and growth arrest in G1 phase of the cell cycle. However, the molecular mechanism underlying UPR-induced G1 cell cycle arrest remains largely unknown. Here we report that activation of the UPR response by tunicamycin (TM), an ER stress inducer, leads to accumulation of p27 and G1 cell cycle arrest in melanoma cells. This accumulation of p27 is due to the inhibition on its polyubiquitination and subsequent degradation upon TM treatment. Correlated with p27 stabilization, the levels of Skp2, an E3 ligase for p27, are decreased in response to TM treatment. More importantly, knockdown of p27 greatly reduces TM-induced G1 cell cycle arrest. Taken together, these data implicate p27 as a critical mediator of ER stress-induced growth arrest.[3]

C₃₉H₆₄N₄O₁₆(N=₁₀)

844.94 (n=10)

844.94 (n=10)

11089-65-9

Off-white to light yellow solid powder

1.4±0.1 g/cm3

234 - 235ºC

1.617

2.58

ZHSGGJXRNHWHRS-VIDYELAYSA-N

InChI=1S/C30H46N4O16/c1-11(2)5-4-6-16(38)32-19-23(43)20(40)14(47-29(19)50-28-18(31-12(3)36)22(42)21(41)15(10-35)48-28)9-13(37)26-24(44)25(45)27(49-26)34-8-7-17(39)33-30(34)46/h4,6-8,11,13-15,18-29,35,37,40-45H,5,9-10H2,1-3H3,(H,31,36)(H,32,38)(H,33,39,46)/b6-4+/t13?,14-,15-,18-,19-,20+,21-,22-,23-,24+,25-,26-,27-,28-,29+/m1/s1

(E)-N-((2S,3R,4R,5R,6R)-2-(((2R,3R,4R,5S,6R)-3-acetamido-4,5-dihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)-6-(2-((2R,3S,4R,5R)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-dihydroxytetrahydrofuran-2-yl)-2-hydroxyethyl)-4,5-dihydroxytetrahydro-2H-pyran-3-yl)-5-methylhex-2-enamide

NSC 177382; NSC177382; NSC-177382

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~33.33 mg/mL
H2O : < 0.1 mg/mL

Solubility in Formulation 1: ≥ 2 mg/mL (Infinity mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2 mg/mL (Infinity mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2 mg/mL (Infinity mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)