ANTI-CANCER COMPOSITION CONTAINING AURANOFIN AND MERCAPTO COMPOUND AND USE THEREOF

Abstract

Disclosed is an anticancer composition containing auranofin and a mercapto compound and the use thereof. The composition contains auranofin and the mercapto compound. By the combined use of auranofin and the mercapto compound, the problem that auranofin cannot effectively inhibit the proliferation of cancer cells under normal physiological condition is solved. When combined with the mercapto compound, auranofin can inhibit tumor growth well, indicating that the combination of auranofin and the mercapto compound can be used as an anticancer drug composition. Moreover, the uptake of auranofin in tumor tissues also can be adjusted by regulating the type of mercapto compound, and thus, providing better selectivity in vivo anti-cancer.

Claims

1. A composition, comprising auranofin and a mercapto compound.

2. The composition according to claim 1, wherein the mercapto compound comprises a compound with a structure as shown in Formula I or a thiolate:
RSH (Formula I); R is selected from any group; and the mercapto compound is one or more of -mercaptoethanol, mercaptoethanamine, methylthioimidazole, propylthiouracil, dithiothreitol, N-acetylcysteine, glutathione, sodium thiosulfate, sodium thiophosphate, sodium diethyldithiocarbamate or 1-thio--D-glucose tetraacetate.

3. A drug, comprising the composition according to claim 1.

4. A cell proliferation inhibitor, comprising the composition of claim 1.

5.-10. (canceled)

11. The cell proliferation inhibitor according to claim 4, wherein the cells comprise colon cancer cells, liver cancer cells, lung cancer cells, gastric cancer cells, cervical cancer cells, and breast cancer cells.

12. A method for treating tumors, comprising administering the composition of claim 1 to a subject in need thereof.

13. The method according to claim 12, the tumors comprise colon cancer, liver cancer, lung cancer, gastric cancer, cervical cancer, and breast cancer.

14. A method for inhibiting cell proliferation, comprising administering the composition of claim 1 to a subject in need thereof.

15. The method according to claim 14, wherein the cells comprise colon cancer cells, liter cancer cells, lung cancer cells, gastric cancer cells, cervical cancer cells and breast cancer cells.

16. A TrxR inhibitor, comprising the composition comprising auranofin and a mercapto compound of claim 1.

17. The TrxR inhibitor according to claim 16, wherein the mercapto compound serves as a synergist of auranofin.

18. The TrxR inhibitor according to claim 17, wherein the mercapto compound comprises one or more of -mercaptoethanol, mercaptoethanamine, methylthioimidazole, propylthiouracil, dithiothreitol, N-acetylcysteine, glutathione, sodium thiosulfate, sodium thiophosphate, sodium diethyldithiocarbamate or 1-thio--D-glucose tetraacetate.

19. A method for inhibiting a TrxR activity of a cell, comprising contacting the composition according to claim 1 with the cell.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 shows the inhibitory effect of auranofin in combination with various mercapto compounds on TrxR activity;

[0043] FIG. 2 shows the effect of auranofin in combination with 1-thio--D-glucose tetraacetate (TGTA) on tumor volume in a mouse tumor model;

[0044] FIG. 3 shows the effect of auranofin in combination with TGTA on weight of mice in a mouse tumor model;

[0045] FIG. 4A and FIG. 4B show the actual effect of auranofin in combination with TGTA in a mouse tumor model, where FIG. 4A is the image of a tumor, and FIG. 4B is the image of a mouse;

[0046] FIG. 5 shows the effect of auranofin in combination with -mercaptoethanol on tumor volume in a mouse tumor model;

[0047] FIG. 6 shows the effect of auranofin in combination with -mercaptoethanol on weight of mice in a mouse tumor model; and

[0048] FIG. 7 shows an image of auranofin in combination with -mercaptoethanol on a tumor in a mouse tumor model.

DETAILED DESCRIPTION

[0049] To better clarify the inventive purpose, technical solution and technical effect of the present disclosure, the present disclosure is further described in detail in conjunction with specific embodiments. It should be understood that the specific embodiments described in the present description are merely intended to explain the present disclosure, but not as a limit to the present disclosure.

[0050] Unless otherwise specified, the experimental materials and reagents used are all conventional consumables and reagents that are commercially available.

[0051] Inhibitory Effect of Auranofin in Combination with Various Mercapto Compounds on the Activity of Various Cancer Cells

[0052] (1) Culture of Cancer Cells

[0053] A flask with the cancer cells required for the experiment, with an original culture solution discarded, was washed for three times with 2 mL of PBS, 1 mL of pancreatin was added for digestion for 30 s, and 2 mL of a medium was added to terminate the digestion. The cells were transferred to a centrifuge tube and centrifuged at 1000 rpm for 3 min, the supernatant was discarded, and 2 mL of a medium was added and blew 10 times to be mixed uniformly. 10 L of a cell suspension was taken for cell counting, and spread on a 96-well plate, with 5000 cells per well and 3 duplications for each compound, and then the number of cells and cell wells was calculated. The amount of required cell suspension and the number of cells for medium dilution were calculated by cell counting. 100 L of medium was plated with 5000 cells per well, pipetted and mixed uniformly, and the cells were inoculated using a volley, placed in an incubator for culture, and marked.

[0054] (2) The cells cultured in step (1) was taken, and discarded with the original medium. Auranofin mother liquor was diluted to a diluent with final concentrations of 0, 0.78125, 1.5625, 3.125, 6.25, 12.5, 25, 50 and 100 M, and mixed uniformly. A volley (using 3 wells) was used to draw 100 L of dilution per well, a 96-well plate was tilted, diluents with each concentration were added in sequence to the corresponding 3 marked wells carefully to prevent poking the cells, blown and sucked about 3 times to be mixed uniformly, marked, shaken for 3 times, and put into a CO2 incubator for culture. The above steps were repeated for each auranofin diluent.

[0055] After auranofin was added for culture for 1 hour, the mother liquor of the mercapto compound was diluted into 1 M and mixed uniformly. A volley (using 3 wells) was used to suck 20 L of diluent per well, the 96-well plate was tilted, the diluents of different mercapto compounds were added in sequence to the corresponding 3 marked wells carefully to prevent poking the cells, blown and sucked about 3 times to be mixed uniformly, and put back to the incubator to continue culture.

[0056] (3) Detection of the Inhibitory Effect on Cancer Cell Proliferation by an MTT Colorimetric Method

[0057] After different mercapto compounds were added to cells for 24 h, 20 L of MTT (with a concentration of 5 mg/mL in PBS) per well was added to the 96-well plate by a volley; and incubation was carried out at 37 C. for 4 h. At the end of incubation, the MTT mixture was sucked out, and DMSO was added at 130 L/well using a volley. The cells were shaken for 10 min, after Formazan was fully dissolved, the absorbance was detected at a wavelength of 490 nm with a microplate reader, the survival rate of the cells at various concentrations of drugs was calculated as required to draw a scatter diagram, and the IC.sub.50 values of auranofin in combination with various compounds (containing 10% fetal bovine serum (FBS) or 40 mg/mL Bovine albumin (BSA)) on the proliferation of cancer cells are as shown in Tables 1 and 2, where auranofin alone (without BSA/FBS) was used as the control. The IC.sub.50 values of auranofin alone are shown in Table 3.

TABLE-US-00001 TABLE 1 Inhibitory effect of auranofin in combination with various mercapto compounds (with 10% FBS) on proliferation of cancer cells IC.sub.50 MCF-7 HCT116 HepG-2 A549 Human Sodium Human Human Human breast - diethyldithio- colon liver lung cell mercapto- carbamate cancer cancer cancer cancer Group Auranofin ethanol (DEDT) cells cells cells cells 1 + 3.4 3.0 12.9 5.7 2 + + <0.625 <0.625 4.0 0.9 3 + + <0.625 <0.625 4.3 Where + means addition.

TABLE-US-00002 TABLE 2 Inhibitory effect of auranofin in combination with 200 M of various compounds (containing 40 mg/mL BSA) on proliferation of cancer cells IC.sub.50 MCF-7 HCT-8 HCTI16 HepG-2 A549 Human Human Human Human Human breast colon - colon liver lung cell adeno- mercapto- Mercapto- cancer cancer cancer cancer carcinoma Group Auranofin ethanol ethylamine TGTA cells cells cells cells cells 1 + 30.0 16.6 70.5 39.7 33.2 2 + + 5.8 2.3 32.1 19.6 15.5 3 + + 15.3 9.8 35.7 15.9 4 + + <1.56 <1.56 Where + means addition.

TABLE-US-00003 TABLE 3 Inhibitory effect of auranofin alone (without BSA/FBS) on proliferation of cancer cells HCT116 HepG2 A549 MCF-7 Human colon Human liver Human lung Human breast cancer cells cancer cells cancer cells cell cancer cells IC.sub.50 1.0 1.3 4.2 3.4 Where + means addition.

[0058] According to the results of Table 1-2, the killing effect of auranofin in combination with various compounds (with 30% FBS) on HCT116 human colon cancer cells and the killing effect of the auranofin-TGTA (50 M) in combination with other cancer cells (lung cancer, colon cancer, breast cancer, liver cancer, cervical cancer and gastric cancer cells) were further detected by using the same method as the above.

[0059] The results are shown in Tables 4 and 5.

TABLE-US-00004 TABLE 4 Killing effect of auranofin in combination with various compounds (with 30% FBS) on HCT116 human colon cancer cells Cell survival rate after Cell survival addition of 10 M Compounds rate (%) auranofin (%) Auranofin 75 5 50 M TGTA 97 5 18 2 50 M -mercaptoethanol 96 15 55 4 50 M mercaptoethylamine 105 7 85 3 50 M DEDT 78 10 0.9 1.6 Methimazole 98 9 87 5 Propylthiouracil 101 6 76 9 Dithiothreitol (DTT) 102 4 88 6 N-acetylcysteine (NAC) 100 6 77 17 Glutathione (GSH) 116 6 81 7 sodium thiosulfate 105 5 84 8 Sodium thiophosphate hydrate 99 8 79 4

TABLE-US-00005 TABLE 5 Effect of auranofin alone, TGTA (50 M) alone, and auranofin in combination with TGTA on cell survival rate in different cell lines Cell colone breast Liver Cervical Gastric survival Lung cancer cancer cancer cancer cancer cancer rate (%) PC9 PCGR A549 HCT116 MCF-7 HepG2 Hela MGC803 TGTA 104 2 101 3 104 6 97 5 99 3 104 4 87 6 104 9 Auranofin 93 3 37 4 81 7 75 5 80 2 87 1 46 7 79 3 Auranofin + 2 1 11 1 .sup.15 0.7 18 2 51 3 15 5 35 4 10 1 TGTA

[0060] Results of Table 1-5 indicate that under the normal physiological condition (the addition of FBS or BSA to an empty medium can simulate the high mercapto environment under physiological condition), auranofin has no significant inhibitory effect on HCT116 human colon cancer cells, A549 human lung cancer cells, MCF-7 human breast cell cancer cells, PC9 human lung cancer cells, Hela human cervical cancer cells, MGC803 human gastric cancer and HepG-2 human liver cancer cells. When a non-toxic dose of mercapto compound is added, auranofin shows an excellent inhibitory effect on all 7 cancer cells.

[0061] Mercapto Compounds Enhanced the Inhibitory Effect of Auranofin on TrxR Activity

[0062] The detection steps were as follows:

[0063] HepG2 cells were used as a test subject.

[0064] The cells were inoculated into a 6-well plate at 210.sup.5 cell/well and incubated for 24 h.

[0065] After the incubation, the cell culture medium was replaced with 30% FBS to simulate the high concentration mercapto environment under the normal physiological condition, and used as a control (without adding any reagents). The experimental group was added with 0.5 M of auranofin for incubation at 37 C. for 30 min, and then added with the mercapto compound (DEDT, -mercaptoethanol or mercaptoethylamine) for incubation for 30 min (final concentration of DMSO in the system was 1%). The incubated cells were washed for 3 times with PBS, added with 100 L of icy lysis buffer (containing 50 mM of phosphate buffer with pH 7.4, 1 mM EDTA, and 0.10% Triton-X 100), and then lysed on ice for 5 min to collect the cell lysate.

[0066] 100 L of buffer (containing 50 mM of potassium phosphate with pH 7.4, 1 mM EDTA, and 0.2 mM NADPH) was added to the collected cell lysate (10 g protein), 5,5-dithiobis (2-nitrobenzoic acid) (DTNB, with a final concentration of 3 mM) was added to initiate a reaction, and the activity of TrxR was obtained on the basis of the increased OD value in 10 minutes (OD detection wavelength was 410 nm). Auranofin alone was the positive control sample, and the blank group was the negative control.

[0067] The results are shown in Tables 6 and FIG. 1.

TABLE-US-00006 TABLE 6 Inhibitory effect on activity of TrxR in each experimental group Activity Group of TrxR Negative control 100% Positive control (without FBS) 15.9% Positive control (with 30% FBS) 63.6% -mercaptoethanol alone (200 M) 127.3% Mercaptoethanamine alone (200 M) 118.2% DEDT alone (200 M) 88.6% Auranofin in combination with -mercaptoethanol (200 M) 20.5% Auranofin in combination with mercaptoethanamine (200 M) 38.6% Auranofin in combination with DEDT (200 M) 18.2%

[0068] As show in Table 6, in the absence of FBS (i.e., simulated in vitro conditions), auranofin can inhibit intracellular TrxR activity to 15.9%; however, under the condition of 30% FBS (simulated in vivo condition), the ability of auranofin to inhibit enzyme activity is reduced, and the intracellular TrxR activity is inhibited to 63.6% only. However, when the mercapto compounds are added, even under the condition of 30% FBS, the ability of auranofin to inhibit enzyme activity is greatly improved. Compared with the absence of the mercapto compounds, the ability of auranofin to inhibit enzyme activity is improved by more than 3 times.

[0069] Effect of Auranofin in Combination with Various Mercapto Compounds on Cell Uptake of Auranofin

[0070] The detection steps were as follows:

[0071] HepG2 cells were used as a test subject.

[0072] The cells were inoculated into a 6-well plate at 210.sup.5 cell/well and incubated for 24 h.

[0073] After the incubation, the cell culture medium was replaced with 30% of FBS to stimulate a high-concentration mercapto environment under the normal physiological condition, and used as a control (without adding any reagents). The experimental group was added with 3 M of auranofin for incubation at 37 C. for 10 min and then added with the mercapto compound (DEDT, -mercaptoethanol or mercaptoethylamine) for incubation for 1 h (final concentration of DMSO in the system was 1%). After incubation, the cells were immediately washed for 3 times with PBS, 500 L of ultrapure water was added to each well to break the cells, and after 15 min, the cell lysate was collected.

[0074] The collected cell lysate was dissolved by adding aqua regia and diluted with ultrapure water to a proper proportion. Inductively coupled plasma mass spectrometry (ICP-MS) was used for gold detection. The cell uptake rate of 3 M chynophon without FBS was used as the control.

[0075] The results are shown in Table 7.

TABLE-US-00007 TABLE 7 Effect on the cell uptake rate of auranofin in each experimental group Group Uptake (mg) Cell uptake rate (%) Control (without FBS) 728.39 100.0 3 M auranofin (30% FBS) 133.15 18.3 Auranofin in combination with 142.31 19.5 mercaptoethanamine (200 M) Auranofin in combination with - 374.91 51.5 mercaptoethanol (200 M) Auranofin in combination with 321.79 44.2 DEDT (200 M)

[0076] Wherein, the above uptake is the amount of gold (mg) in 1 g protein in the cell.

[0077] As shown in Table 7, in the absence of FBS, with reference to auranofin, the uptake of gold reaches 728 mg/g protein. However, when the concentration of FBS in the medium is increased, the uptake of gold is reduced rapidly; and when the mercapto compound (0-mercaptoethanol, DEDT) is added, the uptake of auranofin is greatly increased. This indicates that the absorption of auranofin in cells is improved after the mercapto compound is added.

[0078] Actual Inhibitory Effect of Auranofin in Combination with Various Mercapto Compounds in Mouse Tumor Model

[0079] The detection steps were as follows:

[0080] Establishment of mouse tumor model: 2 million colon cancer cell HCT116 cells suspended in PBS were injected subcutaneously into the dorsal side of 5-7 week-old female BALB/Cann nu (Nude) mice to establish a xenograft model.

[0081] When the tumor volume reached about 50 mm.sup.3 (3-4 days after tumor inoculation), mice were randomly divided into a control group and a treatment group, the control group was treated with corn oil, the treatment group was intraperitoneally injected with auranofin (3 mg/kg mouse body weight/day) in combination with various mercapto compounds (-mercaptoethanol or TGTA, 40 mg/kg mouse body weight/day) once a day. When the tumor volume grew to 1000 mm.sup.3, the mice were anesthetized and then sacrificed by dislocation of the cervical spine.

[0082] The results are shown in FIGS. 2-7.

[0083] The growth of tumors was not effectively inhibited in the control group, the auranofin alone group or the mercapto compound alone group. When auranofin and the mercapto compound were used in combination, the tumor growth was inhibited greatly.

[0084] The above embodiments are the optimal implementations of the present disclosure, which however are not limited by the embodiments, and any other changes, modifications, substitutions, combinations, simplifications made without deviating from the spirit and principle of the present disclosure shall be equivalent substitution methods, which all fall within in the protection scope of the present disclosure.