New human microvascular endothelial cell lines with specific adhesion molecules phenotypes.

Vascular endothelial cells recognize blood-borne circulating cells and allow them to extravasate in a tissue-specific manner. Because this property determines the selectivity of lymphocyte homing, it is fundamental in physiological as well as pathological processes (inflammation, autoimmune diseases, metastasis). As a tool to assess the molecular basis of endothelium selectivity, microvascular endothelial cell lines of distinct tissue origin were established. Endothelial cells, isolated from lymphoid tissues (lymph nodes and appendix) and from nonlymphoid immune sites--intestine, lung, and skin--were immortalized in vitro. Their general endothelial characteristics, such as the presence of von Willebrand factor (wWf), angiotensin-converting enzyme (ACE), VE-cadherin, and the intracellular E-selectin, were preserved. This article shows that these cell lines display phenotypic characteristics related to their tissue origin. Hence, endothelial cells from lymph nodes expressed peripheral lymph node addressins (PNAds). Endothelial cells from nonlymphoid tissues were ICAM-1 (intercellular adhesion molecule-1) and CD49e positive, whereas P-selectin was not equally distributed among the cell lines. Endothelial cells from mucosal sites reacted with antibody against human MAdCAM-1 (mucosal addressin cell adhesion molecule). In the adhesion test, lymphoid and myeloid cells adhere to endothelial cell lines in a distinct manner. These lines could be useful to study molecular mechanisms involved in tissue-specific cell-cell interaction.

Chemoimmunotherapy of cancer: potentiated effectiveness of granulocyte-macrophage colony-stimulating factor and ifosfamide derivative CBM-4A.

The effectiveness of combined chemoimmunotherapy with ifosfamide derivative CBM-4A and granulocyte-macrophage colony-stimulating factor (GM-CSF) was investigated in two experimental tumor models, 3MC-induced MHC class I+ sarcoma Mc12 and HPV16 E6/E7 oncogene-induced MHC class I- carcinoma MK16, transplanted in syngeneic mice. Treatment of Mc12 and MK16 tumor-bearing mice with GM-CSF or CBM-4A alone produced moderate anti-tumor effects. However, when the tumor-bearing mice were first treated i.p. with a single dose of CBM-4A (150 mg/kg) and three days later peritumorally with five daily doses of GM-CSF (100 ng/day), substantially stronger tumor-inhibitory effects were observed. The results indicate that in both, MHC class I+ and MHC class I- tumors, the combined chemoimmunotherapy can inhibit tumor progression more effectively than GM-CSF therapy or chemotherapy alone, and they suggest that GM-CSF should be considered as adjuvant to chemotherapy in clinical trials with HPV 16-associated neoplasms.

Potentiation of the antiproliferative effect in vitro of doxorubicin, cisplatin and genistein by new analogues of vitamin D.

Numerous vitamin D3 analogues have been synthesised in recent years in order to obtain compounds with a favourable biological and therapeutic (antipsoriatic and/or antitumour) activity. Our results showed that pre-treatment for 72 hours of HL-60 human promyelocytic leukaemia cells with calcitriol or its new analogues significantly potentiated their sensitivity to the antiproliferative effect in vitro of cisplatin, doxorubicin or genistein. Moreover, for all cytotoxic agents tested a synergistic antiproliferative effect was observed. This effect was expressed as a significant decrease of the ID50 (inhibitory dose 50%) values for each cytotoxic agent applied after pretreatment with calcitriol or its analogues of HL-60 cells in comparison with the effect of cytotoxic agent applied alone. The observed in vitro potentiated antiproliferative effect of cytotoxic drugs used in combination with vitamin D or its analogues may raise the question as to whether such an effect could be expected in the in vivo situation.

(S)-(-)-Bromofosfamide (CBM-11): synthesis and antitumor activity and toxicity in mice.

(S)-(-)-Bromofosfamide (CBM-11), an enantiomerically pure bromo analog of ifosfamide, was found to be potent against several model tumors in mice. Therapeutic indices of CBM-11 were more favorable as compared to those received for ifosfamide.

Antiangiogenic and antitumour effects in vivo of genistein applied alone or combined with cyclophosphamide.

The antitumour and antiangiogenic effects in vivo of genistein, applied alone or in combined therapy with cyclophosphamide, in the Lewis lung carcinoma (LL2) and B16 melanoma mouse tumour models, were analysed. Our own new method, allowing quantification of the volume of blood present in tumour tissue, enabled estimation of the degree of vascularization. Tumour cells entrapped in alginate beads were injected subcutaneously into mice. The quantification of alginate implant vascularization was performed with 125I-labeled mouse albumin injected intravenously. In mice bearing transplantable Lewis lung cancer the additive antiangiogenic, but not cytostatic, effect of genistein combined with cyclophosphamide (CY) was observed, since the treatment with genistein alone reduced tumour blood supply in 35% (tumour weight in 36%), with CY in 38% (tumour weight in 70%) and with both compounds in 61% (tumour weight in 75%). In the B16 melanoma model the respective values were: 60 and 44% for genistein, 83 and 79% for CY and 76 and 74% for combined treatment. These results indicate a higher antiangiogenic rather than cytostatic effect of genistein in both mouse tumour models applied.

Antiproliferative activity in vitro of new malatoplatinum(ll) complexes.

The results of studies on antiproliferative activity in vitro of nine new platinum(II) complexes against cells of eight human and six murine neoplastic cell lines are described. New complexes with the anionic rest originating from enantiomeric forms of hydroxydicarboxylic malic acid were synthesized to obtain agents with increased water solubility and decreased toxicity. Three compounds, coded 1-3, with ethylenediamine as a neutral ligand, showed cytotoxic activity against 12 out of 14 target cell lines. Their cytotoxic activity was similar or even slightly higher than that of the reference carboplatin. The remaining six compounds, coded 4-9, with 1-alkylimidazole as a neutral ligand, revealed rather low cytotoxic activity, and only against the cells of the human bladder cancer cell line Hu1703He, ovarian cancer cell line OAW-42 and mouse leukemia P388. Most of them appeared to be negative against all other cell lines. No compounds, including reference carboplatin, showed any cytotoxicity against the cells of the T47D human breast cancer cell line or B16F-10 mouse melanoma cell line. The results obtained are in accordance with common opinion, i.e. that the presence of neutral amine ligands with NH groups is required for the cytotoxic activity of platinum complexes. Compounds with a primary amine (ethylenediamine) showed higher cytotoxic activity in vitro than complexes with a tertiary amine (1alkylimidazole).

Antitumour and antimetastatic effect of genistein alone or combined with cyclophosphamide in mice transplanted with various tumours depends on the route of tumour transplantation.

In the present study we evaluated the antitumour effect of genistein alone, cyclophosphamide alone and as a combined therapy with both agents in mice transplanted with B16F-10 melanoma and Lewis lung cancer cells. The influence of the route of inoculation of the tumour cells on the antitumour and antimetastatic effects of these therapeutics was evaluated. The antitumour effect of genistein in mice with B16F-10 intradermically (i.d.) growing tumours and in mice with LL2 subcutaneous (s.c.) tumours was observed. In addition, its antimetastatic effect (reduction of lung colonies) in mice inoculated intravenously (i.v.) with B16F-10 and in mice with LL2 cells injected either intravenously or subcutaneously was observed. No life span prolongation of mice injected intraperitoneally (i.p.) with B16F-10 cells was observed, either after treatment with genistein alone or with cyclophosphamide alone. The synergistic effect of both agents in combined treatment, when the cells of B16F-10 melanoma were injected i.p., i.v. or i.d. and in a weaker manner when the cells of LL2 cancer were injected s.c., was observed. When LL2 cells were injected intravenously, no additive effect of genistein and CY could be detected. In conclusion, we have described the experimental mouse tumour models in which both the antitumour and antimetastatic effects of genistein alone, CY alone and those of combined therapy with genistein and cyclophosphamide were dependent on the implantation route of the tumour cells.

Biological activity in vitro of side-chain modified analogues of calcitriol.

The results of our studies on the biological activity of side-chain modified analogues of vitamin D are reviewed. These analogues appeared to be effective in induction of cell differentiation, inhibition of tumour cell proliferation in vitro and in increasing of antitumour effect of cytostatics. On the other hand, inhibition of cytostatic-induced apoptosis by these compounds was observed. The mechanism of the antiproliferative effect of calcitriol analogues in vitro is discussed. The induction of antigens CD14 and CD11b expression and phagocytic activity of HL-60 cells after exposure to these compounds is related to their effect on cell differentiation. The differentiation of the HL-60 leukaemia cells induced by side-chain modified analogues of calcitriol increases their sensitivity to the antiproliferative effect of cisplatin, doxorubicin and genistein, despite of that this pretreatment causes resistance of these cells to cytostatics-induced apoptosis. We observed a synergistic antiproliferative effect of the combined therapy using analogues of calcitriol with subsequent treatment with the above-mentioned cytostatics. This effect was measured as a significant decrease of the ID50 values for each cytostatic applied after pretreatment of the tumour cells with the calcitriol analogues. The results presented suggest that the improved therapeutic effect may be achieved also in vivo by the combined application of the analogues (without calcemic activity) of calcitriol with antitumour agents.

Metastatic potential of human uroepithelial cancer cells is not dependent on their adhesion to E-selectin.

In our previous studies we have found that human uroepithelial cell lines differ in their expression of sialosyl LewisA antigen. We have also shown that among the studied cell lines, only Hu 1703He cells with the highest expression of this tetrasaccharide bind to E-selectin-expressing cells. In the present study we put forward the question, of whether sialosyl LewisA-mediated adhesion of uroepithelial cells to E-selectin is important in the formation of metastases. The HCV 29T and Hu 1703He cells, representing two uroepithelial cell lines, were transplanted into NCr nu/nu mice. Hu 1703He cells express on their surface a high level of sialosyl LeA antigen, while HCV 29T cells are sialosyl LewisA-negative. We have shown that human uroepithelial cancer cells, in addition to their tumorigenic and invasive properties, are highly metastatic when inoculated into athymic nu/nu mice. The ability to form secondary tumour foci in lung and liver seems to be independent of the expression of sialosyl LewisA antigen.

Cytotoxic and antitumor effect of fibrinogen-methotrexate conjugate.

In this paper we describe the chemical procedure of fibrinogen-methotrexate (F-MTX) conjugate preparation and its in vitro and in vivo antitumor activity. F-MTX conjugates were synthesized in reaction of fibrinogen with MTX N-hydroxysuccynimide ester. The conjugates were not cross-linked and were soluble in water. The results of the in vitro and in vivo studies have shown: (1) a lower in vitro cytotoxicity of the F-MTX conjugate as compared with MTX alone; (2) a significantly higher in vivo antitumor activity of the F-MTX conjugate in mice with P388 leukemia as compared with MTX alone; (3) a significantly increased in vivo lethal toxicity of F-MTX as compared with MTX. The results suggest the therapeutic utility of the fibrinogen-methotrexate conjugate and the usefulness of fibrinogen as a chemotherapeutic drug carrier. However, a new effort in the preparation of F-MTX conjugate should be made to decrease its in vivo toxicity.

The role of GABA-ergic system in human mammary gland pathology and in growth of transplantable murine mammary cancer.

In this paper we described the results of our studies on the baclophen (gamma aminobutyric acid (GABA)-B receptor agonist) inhibitory effect on the growth of experimental mammary cancer 16/C in mice and on the estimation of GABA level and GAD (glutamine acid decarboxylase--the key enzyme in GABA synthesis) activity after this treatment in mice. The experimental data are confronted with the estimation of GABA level and GAD activity in human mammary gland material taken from the patients with benign breast tumors of different pathological and age related hormonal stages. A significant inhibition of 16/C tumor growth in treated with baclophen mice was observed. Mean GABA level and GAD activity were significantly higher both in tumor and in normal tissue of baclophen treated mice in comparison to control animals. The results of clinical studies have shown that the lowest GABA level and GAD activity in tumor and normal mammary gland tissue was detected in patients in peri-menopausal stage. Both, in human and mouse material, the GABA level and GAD activity were higher in tumor than in normal tissue and there was a clear positive correlation between GABA level and GAD activity in both tissues studied. GABA level and GAD activity in tumor and in normal tissue were lower in patients with dysplasia than in patients with fibroadenoma. Considering our results, namely an inhibitory effect of GABA receptor agonist on mammary cancer growth and the correlation between GABA level and the stage of breast pathology and/or hormonal activity, it seems probable that GABA-ergic system is involved in hormonal regulation and pathogenesis of breast cancer.

The antitumor effect of postoperative treatment with genistein alone or combined with cyclophosphamide in mice bearing transplantable tumors.

Genistein has been shown to be an inhibitor of tumor growth as well in vitro as in vivo. In addition to its antitumor effect, genistein reveals the antimetastatic and antiangiogenic properties. In this paper we described the results of our studies on the antimetastatic activity of genistein alone or combined with cyclophosphamide (CY) in mice which before this treatment were exposed to surgical excision of the primary tumor. Three transplantable subcutaneously growing mouse tumors were applied: Lewis lung cancer (LL2), B16F-10 melanoma and 16/C mammary cancer. The antitumor and antimetastatic effect was evaluated by the estimation of a number of lung colonies and a number of primary tumor recurrence as compared to the control mice exposed to the s.c. tumor extirpation only. Twenty days after the surgery, an average of 52 lung tumor colonies per mouse were detected in control mice bearing LL2 cancer. The treatment with genistein resulted in the reduction of the lung colonies to 24 per mouse. The treatment with CY reduced the number of lung colonies to 12 (p < 0.05) and combined treatment with both agents to 4 (p < 0.05). The percentage of primary tumor recurrence was 25, 86, 67 and 80% in the control, genistein treated, CY treated, and genistein + CY treated mice, respectively. Twenty days after the surgery, no lung metastases in the control mice bearing B16F-10 melanoma were observed. The percentage of primary tumor recurrence in the control, genistein treated, CY treated and genistein + CY treated mice was: 86, 29, 57 and 67% respectively. Two different protocols of the treatment with genistein were applied in 16/C mammary cancer model. In the first one genistein was injected before and in the other after surgical excision of tumor. The histological examination revealed the presence of lung metastases in all, untreated and treated, according to both protocols groups of mice. The percentage of primary tumor recurrence in the control mice, genistein treated according to the protocol I, and II was: 100, 40, and 40%, respectively.

Antitumor effect of electrochemical therapy on transplantable mouse cancers.

The aim of our study was to assess the antitumor effect of electrochemical therapy (ECT) in the mice bearing advanced transplantable tumours. Mouse mammary cancer 16/C (group 1) and fibrosarcoma F69-3 (group 2) were transplanted subcutaneously (s.c.) into the C3H or BALB/c mice, respectively. Twenty animals in each group bearing measurable s.c. tumours were randomly divided into two subgroups (experimental and control). Two electrodes were inserted into tumours and low level direct current (6-7 V, 5-21 mA) was passed. The animals were observed and tumors were measured twice a week. The animals were sacrificed and autopsied when the tumor diameter reached 2.0 cm. Two animals of each group (experimental and control) were sacrificed for histopathological tumor examination on the 1st and 6th day after ECT. A significant inhibition of tumor growth in mice subjected to ECT was observed, both in those with s.c. growing mammary cancer and with fibrosarcoma. This inhibition was associated with marked prolongation of survival time of ECT-treated mice. It appeared that the mice with mammary cancers were more susceptible to ECT therapy than those with growing s.c. fibrosarcoma. The histopathological studies of tumor specimens from ECT-treated mice showed extensive foci of necrosis with shrinkage of cell nuclei deprived of chromatin. In conclusion, the treatment which inhibits the growth of experimental mammary and fibrosarcoma tumors was demonstrated. However, in no mice complete regression of tumours was observed.

8,11-dihydroxy-6-[(aminoalkyl)amino]-7H-benzo[e]perimidin-7-ones with activity in multidrug-resistant cell lines: synthesis and antitumor evaluation.

The synthesis of dihydroxybenzoperimidine derivatives, which are chromophore-modified dihydroxyanthracenediones with an additional pyrimidine ring incorporated into the chromophore, is reported. These derivatives are structurally related to the antitumor agent mitoxantrone. Their synthesis was carried out by the reaction of 6-amino-8,11-dihydroxy-7H-benzo[e]perimidin-7-one (5) or 6,8, 11-trihydroxy-7H-benzo[e]perimidin-7-one (10) with a number of respective (alkylamino)alkylamines. The dihydroxybenzoperimidine derivatives exhibited in vitro cytotoxic activity against murine leukemia L1210 and human leukemia HL60 cell lines comparable to that of mitoxantrone. These compounds also exhibited a range of in vitro activity against the human MDR-type resistant leukemia K562R cell line with the MDR phenotype. The most active compound of this series, namely 6a, exhibited potent in vitro cytotoxic activity against a panel of human cell lines. Furthermore, in contrast to both mitoxantrone and doxorubicin, it displayed little cross-resistance in cell lines characterized by a MDR phenotype. Cell cycle analysis in the sensitive HT-29 and mitoxantrone-resistant HT-29/Mx (not identified resistance mechanism) cell lines has revealed that both mitoxantrone and 6a induce a G2/M block. However, while the proportion of apoptotic cells after mitoxantrone treatment is similar for both sensitive and resistant cell lines, it is much lower for 6a. Compound 6a tested against P388 murine leukemia in vivo displayed a significant antitumor effect (%T/C 196 at an optimal dose of 10 mg/kg). The property of overcoming the cross-resistance was maintained also in in vivo efficacy studies, where no difference was observed in the antitumor activity of compound 6a against the A2780 human tumor xenograft and its MDR A2780/Dx subline. We conclude that benzoperimidines, if properly substituted, constitute a novel class of compounds that can overcome multidrug resistance.

GABA level and GAD activity in human and mouse normal and neoplastic mammary gland.

Our studies have demonstrated that GABA (gamma-aminobutyric acid) is detectable both in mouse and in human normal mammary gland and in neoplastic alterations. We have also shown that GABA content in tumor was significantly higher than in normal tissue. The statistically significant difference in GAD (glutamine acid decarboxylase) activity between tumor and normal mammary tissue was also detected. The positive correlation between GABA content and GAD activity in tumor cells was observed both in human and in mice materials. The observed increase in GABA level and GAD activity in tumor tissue could reflect an eventual local antitumor immune response, however, a hypoxia of tumor cells could also be considered. The role of GABA, GAD and GABA-ergic receptors in cancerogenesis and in cancer progression is still to be clarified and requires further studies; however, it may indicate that the known agonists of GABA-ergic system (e.g. baclofen) can potentially modulate the tumor growth.

Synergistic antitumour effects of chemo-immunotherapy with an oxazaphosphorine drug and IL-2-secreting cells in a mouse colon cancer model.

The therapeutic efficacies of two chemical agents-cyclophosphamide (CY) and compound CBM-11-were compared in a chemo-immunotherapy protocol combining a single injection of a cytotoxic agent with a series of weekly peritumoural (p.t.) administrations of non-tumourigenic plasmocytoma cells engineered to produce interleukin-2 (IL-2). Compound CBM-11, an optically active S(-) isomeric form of a bromine-substituted analogue of ifosfamide, is currently used in Phase I clinical trials in Poland. The treatment was applied to mice bearing well-established subcutaneous (s.c.) MC-38 colon tumours. Single intraperitoneal injection of 200 mg/kg of CY or of an equitoxic dose of 140 mg/kg of CBM-11 alone resulted in a tumour growth delay (TGD) of 10-13 and 17-21 d, respectively. This effect was accompanied by an increase in life-span (ILS) of at most 42 and 62% over control. Complete responses (CR) were not observed. Combination of CY or CBM-11 with 6-7 p.t. injections of IL-2-secreting cells resulted in potentiation of the therapeutic effects: TGD and ILS values were considerably increased and long-lasting CRs were observed. The overall incidence of CR after combined treatment was ca 16% and 42% for CY and CBM-11, respectively (P=0.049). A specific anti-MC-38 immunity was induced by the treatment, as verified by rechallenge of cured mice with MC-38 tumour cells 3-4 months post therapy cessation. Our results indicate that tumour destruction by chemotherapy (even if not complete) and prolonged local delivery of IL-2 secreted by allogeneic cells of an easy to culture line are sufficient to secure long-lasting specific antitumour immunity in cured mice.

Synthesis, and cytotoxic activity of some novel indolo[2,3-b]quinoline derivatives: DNA topoisomerase II inhibitors.

A series of new 5H-indolo[2,3-b]quinoline derivatives bearing methoxy and methyl groups at C-2 and C-9 was synthesized (according to the modified Graebe-Ullmann reaction). These compounds were evaluated for their antimicrobial and cytotoxic activity and tested as inhibitors of DNA topoisomerase II. Lipophilic and calf thymus DNA binding properties of these compounds were also established. In the SAR studies we used quantum-mechanical methodology to analyze the molecular properties of the drugs. All of the 5H-indolo[2,3-b]quinolines tested were found to inhibit the growth of gram-positive bacteria and pathogenic fungi at MIC ranging between 2.0 and 6.0 microM. They showed also cytotoxic activity in vitro against several human cancer cell lines of different origin (ID50 varied from 0.6 to 1.4 microM), and stimulated the formation of topoisomerase-II-mediated pSP65 DNA cleavage at concentration between 0.2 and 0.5 microM. The most active indolo[2,3-b]quinolines which had the greatest contribution to the increase in the Tm of DNA displayed also the highest DNA binding constants and the highest cytotoxic activity. The differences in DNA binding properties and cytotoxic activity seem to be more related to steric than electrostatic effects.

Microbial conversion of methyl- and methoxy- substituted derivatives of 5H-indolo[2,3-b]quinoline as a method of developing novel cytotoxic agents.

In furtherance of our structure-activity relationship studies on the antitumor activity of indolo[2,3-b]quinolines, novel cytotoxic derivatives bearing methyl groups at N-5, C-11, C-2 and/or C-9, as well as methoxy-groups at C-2 and/or C-9, were synthesized by the modified Graebe-Ullmann reaction. To elucidate the metabolic pathways of these compounds, zygomycete fungus Cunninghamella elegans ATCC 9245 (which is known to produce drug metabolites that are also formed in mammals) was used as a mimetic organism. Simultaneously, biotransformation of the same substrates was carried out with a microsomal fraction of rat liver. Three forms of microbial conversion were observed: hydroxylation of the aromatic ring or hydroxylation of the methyl group, and O-demethylation. The reaction proceeded regioselectively, and only positions C-2 and C-9 were affected in the indolo[2,3-b]quinoline system. The products formed were found to be identical with the metabolites generated by rat liver microsomes. The metabolites obtained displayed a cytotoxic activity in vitro against colon adenocarcinoma SW-707 and lung carcinoma A-549 (ID50 in the range 0.27-3.04 microM), which was as strong as that of the substrates. In the course of the further metabolic pathway study of indolo[2,3-b]quinolines we found that metabolites with a hydroxyl group in the aromatic system were transformed to non-cytotoxic polymeric products by multicopper oxidases: human ceruloplasmin or fungal laccase (used as mimetic enzyme), whereas metabolites with a hydroxymethyl group did not undergo such bioconversion. The last mentioned compounds can be regarded as a novel type of cytotoxic indolo[2,3-b]quinoline derivatives formed in metabolic processes.

Antiproliferative activity in vitro of side-chain analogues of calcitriol against various human normal and cancer cell lines.

The antiproliferative in vitro activity of side-chain modified analogues of 1,25-dihydroxyvitamin D3 was examined in order to select compounds with potential antitumour activity. Analogues PRI-1906, PRI-1907, PRI-1909, PRI-2191, PRI-2192, PRI-2193 and PRI-2194 were examined for their antiproliferative activity in vitro against a spectrum of various human cancer cell lines using the MTT technique. In addition, analogues PRI-1906 and PRI-2191 were screened against cells of human leukaemia HL-60 line and against normal human skin fibroblasts. Calcitriol and these two analogues revealed strong antiproliferative activity against these two targets with maximal growth inhibition of 68% for HL-60 cells and of 60% for fibroblasts, and this effect was dose dependent. All analogues tested, except PRI-1909, revealed antiproliferative activity against human carcinoma cell lines of breast origin applied, namely against T47D and MCF-7. The maximal growth inhibition of 49% for T47D cell line and 39% for MCF-7 line was observed, and this effect was dose dependent. The inhibitory doses of the analogues tested were compared with the indices for calcitriol. Analogue PRI-1906 revealed the strongest antiproliferative activity against these four target cell lines (HL-60, fibroblasts, MCF-7, and T47D). The novel analogues of calcitriol, similarly to calcitriol, appeared to be not active against other human cancer cell lines tested (including those originated from lung, colon, prostate, urinary bladder, ovary, pancreas, stomach and kidney) revealing an antiproliferative activity not exceeding 20%. The mechanism of the observed antiproliferative effect of calcitriol and its analogues in vitro remains unclear, however, it may be related to their effect on cell differentiation. The appearance of antigen CD14 and CD11b expression after exposure to calcitriol and its new analogues confirmed their effect on cell differentiation.