Much efforts have been made to obtain active and less toxic vitamin D analogs for new clinical applications. In the previous studies, we have demonstrated that 1,24-(OH)₂D₃ revealed a potent antiproliferative effect against various cancer cell lines in vitro and this effect was stronger than obtained with parental 1,25-(OH)₂D₃. Moreover, we have shown that this effect could be attributed to induction of cancer cell-differentiation. Our results indicate, that 1,24-(OH)₂D₃ exhibits lower calcemic activity as well as toxicity than calcitriol.

In the present study we have evaluated the antitumor effect of combined treatment with cisplatin or fluorouracil and vitamin D analog and analyzed the serum calcium level in tumor (WEHI-3) bearing mice.

Single therapy with cisplatin reduced tumor volume with tumor growth inhibition (TGI) of 74%. For 1,24-(OH)₂D₃ we obtained 45% TGI value. However, combined treatment led only to subadditive effect. For fluorouracil we obtained 67% TGI value and for combined treatment 91% - what meant synergistic effect between cytostatic and vitamin D analog. Combined treatment did not cause an increase in life-span in comparison to applying either agent alone. The toxicity of combined treatment was the same as a singular drug treatment.

In conclusion, combined treatment of cisplatin and 1,24-(OH)₂D₃ lead to subadditive effect and fluorouracil with this vitamin D derivative lead to synergistic effect in reducing tumor volume.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/6507 must be provided.

1. The comparison of the stability indicating  two HPLC methods and their application for the determination of bosentan in coated tablets 
2. Synthesis of new 5H-indolo[2,3-b]quinoline derivatives with a high selective cytotoxic activity
3. What modern crystallography can add to pharmaceutical research?
4. Administration of isothiocyanate-derived mercapturic acids inhibits solid tumor growth of 4T1 murine mammary carcinoma cells in BALB/c mice
5. Antiproliferative and cytotoxic effect of vitamin D₃ and its derivatives on the selected cells with a higher proliferative potential
6. Preliminary studies on application of library of artificial receptors for differentiation of metabolites in urine of healthy and cancer mice
7. Starch derivatives as vehicles for drug delivery in anticancer therapy
8. Mercapturic acids as a naturally occurring isothiocyanates prodrug form with site-directed delivery system built-in based on an oxidative environment of the tumor
9. Synthesis and biological activity of novel N,N-cyclic-2,4-dihydroxythiobenzamide derivatives
10. Anticancer activity of vitamin D, genistein and indoloquinoline analogs
11. Pharmaceutical  technologies  – why do they have to be innovative
12. A novel convergent synthesis of the prostaglandin F_2α analogues
13. Synthesis and anticancer activity of acetylenic derivatives of betulin
14. Comparative permeation studies of tacalcitol through the human skin from brand product versus generic product
15. Interaction of endotoxin and polymyxin B in B16 mouse melanoma model of metatstasis
16. Anticancer activity of the conjugates:  modified fibrinogen – methotrexate.
17. Synthesis and cytotoxic activity of new Pt (II) complexes with nitropyrazoles in aerobic and hypoxic conditions
18. Vitamin D analogs enhance the activity of imatinib mesylate in human non-small cell lung cancer model
19. Colon cancer treatment with the use of vitamin D analogs and irinotecan 
20. Novel bifunctional synthetic isothiocyanates with high antiproliferative activity
21. Naturally occurring hydroxyalkyl isothiocyanates and isothiocyanatoalkyl benzoates - structure-activity and structure-mechanism of action relationship studies.
22. Synthesis and biological evaluation of new amino acid and dipeptide derivatives of neocryptolepine as anticancer agents. 
23. Experimental and theoretical charge density studies on a model analogue of vitamin D
24. Synthetic Technologies of Pharmaceutical Substances
25. Antitumor activity of carrier-methotrexate conjugates.
26. CLA derivatives as functional food compounds
27. New acetylenic derivatives of betulin with anticancer activity
28. Catalytic synthesis and antiproliferative activity in vitro of polisubstituted isoxazolopyridine derivatives.
29. Steroid profile of Asplenium cuneifolium
30. The influence of (24R)-1,24- dihydroxyvitamin D₃ on the anticancer activity of 5-fluorouracil in human colon cancer model
31. Comparison of antiproliferative activity of the natural isothiocyanates and their mercapturic derivatives.
32. Could the calorically restricted ketogenic diet be an     effective alternative or supportive therapy for breast cancer?
33. The use of the hyphenated LC-MS/MS technique for the characterisation of impurity profile of Quetiapine during drug development
34. A novel synthesis of 19-nor analogs of vitamin D
35. Analogs of genistein and its possible anti-metastatic properties
36. The influence of novel analogs of vitamin D₃ on the antiproliferative activity of cisplatin or doxorubicin on human promyelocytic leukaemia cell line HL-60 
37. New amino acid and peptide derivatives of 5H-indolo[2,3-b]quinoline and their biological activity.
38. The cytotoxic activity of glycosides of indolo[2,3-b]quinoline derivatives.
39. Disubstituted indolo[2,3-b]quinoline derivatives - the cytotoxic activity in vitro against various human tumor cell lines.
40. Mono substituted 5H- and 6H-indolo[2,3-b]quinoline derivatives and their ability to overcome the barrier of drug resistance.
41. Isolation, structural elucidation and characterization of impurities in latanoprost
42. New rosiglitazone salts
43. Synthesis and antiproliferative activity in vitro of (4-substituted-2-butynylthio)quinolines
44. New calcipotriol analogs, their toxicity and antitumor activity in vivo in comparison to the affinity with VDR and DBP
45. Synthesis and cytostatic activity of new 1-substituted 6H-pyrido[4,3-b]carbazole derivatives
46. High-yielded method of synthesis of voriconazole.
47. The new analogs of genistein decrease mitochondrial membrane potential and activate caspase-3
48. New amino acid derivatives of 6H-indolo[2,3-b]quinolines
49. Polimorphism of Active Pharmaceutical Ingredients
50. Influence of Transformation of the Amino Group in Anthracyclines into -N=CH-N< or -N=CH-O- Group on Their Biological Properties
51. PRIMARY CYTOTOXICITY EVALUATION OF NEW HETEROCYCLIC SYSTEMS WITH PYRIDODIAZEPINE.
52. SYNTHESIS AND ANTIPROLIFERATIVE ACTIVITY IN VITRO OF NEW 2-AMINOBENZIMIDAZOLE DERIVATIVES. PART 3. REACTIONS OF 2-ARYLIDENE- AMINOBENZIMIDAZOLE WITH SELECTED 1,3-DIKETONES.
53. CONJUGATED LINOLEIC ACIDS PREPARATIONS AS EFFECTIVE NUTRACEUTICS
54. THE ANTIMETASTATIC EFFECT OF BACTERIOPHAGE T4* ADMINISTRATED IN COMBINED TREATMENT WITH SELECTED CYTOSTATICS IN MICE WITH B16 MELANOMA
55. SYNTHESIS AND ANTIPROLIFERATIVE ACTIVITY OF DIACETYLENIC THIOQUINOLINES
56. SYNTHESIS AND CYTOTOXIC ACTIVITY OF 10-DEACETYL-10-PROPARGILPACLITAXEL
57. THE CYTOTOXIC GLYCOSIDES OF INDOLO[2,3-B]QUINOLINE DERIVATIVES. IN VITRO AND IN VIVO STUDIES
58. MONO SUBSTITUTED 5H-INDOLO[2,3-B]- QUINOLINE DERIVATIVES AND THEIR ABILITY TO OVERCOME THE BARRIER OF DRUG RESISTANCE.
59. DISUBSTITUTED INDOLO[2,3-b]QUINOLINE DERIVATIVES. THE CYTOTOXIC ACTIVITY IN VITRO AGAINST VARIOUS HUMAN TUMOR CELL LINE.
60. SYNTHESIS AND CYTOTOXIC ACTIVITY OF NEW 1-SUBSTITUTED PYRIDO[4,3-b]CARBA- ZOLE DERIVATIVES
61. FIRST ROUND STUDIES ON LEWIS LUNG CARCINOMA ACTIVITY OF THE NEW LEAD STRUCTURES IN THE ISOXAZOLE HETEROCYCLIC SYSTEM
62. CONJUGATES OF METHOTREXATE AND DEXTRANS IN MOUSE LEUKEMIA MODEL WITH MULTIPLE DOSE SCHEDULE
63. GENISTEIN, ITS NEW ANALOGS AND COMPLEXES - THE ANTIPROLIFERATIVE EFFECTS ON HL-60 LEUKEMIA CELL LINE
64. COMBINATION OF: IMATINIB, PRI-2191 AND CYTOSTATICS - THE ANTIPROLIFERATIVE EFFECTS ON HL-60 LEUKEMIA CELL LINE
65. DICARBOXYLATOPLATINUM(II) COMPLEX - SIX TIMES LESS TOXIC THAN CARBOPLATIN
66. ANTIPROLIFERATIVE ACTIVITY IN VITRO OF DIASTEREOMERIC ANALOGUES OF VITAMIN D3 AGAINST NORMAL AND CANCER CELL LINES