tacrolimus and Breast-Neoplasms

The primary source of failure of cancer therapies is multidrug resistance (MDR), which can be caused by different mechanisms, including the overexpression of ABC transporters in cancer cells. Among the 48 human ABC proteins, the breast cancer resistance protein (BCRP/ABCG2) has been described as a pivotal player in cancer resistance. The use of functional inhibitors and expression modulators is a promising strategy to overcome the MDR caused by ABCG2. Despite the lack of clinical trials using ABCG2 inhibitors, many compounds have already been discovered. This review presents an overview about various ABCG2 inhibitors that have been identified, discussing some chemical aspects and the main experimental methods used to identify and characterize the mechanisms of new inhibitors. In addition, some biological requirements to pursue preclinical tests are described. Finally, we discuss the potential use of ABCG2 inhibitors in cancer stem cells (CSC) for improving the objective response rate and the mechanism of ABCG2 modulators at transcriptional and protein expression levels.

Topics: Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 2; Breast Neoplasms; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Female; Humans; Neoplasm Proteins; Neoplastic Stem Cells

Renal toxicity has been reported with bisphosphonates such as pamidronate and zolidronate but not with ibandronate, in the treatment of breast cancer patients with bone metastasis. One of the patterns of bisphosphonate-induced nephrotoxicity is focal segmental glomerulosclerosis (FSGS) or its morphological variant, collapsing focal segmental glomerulosclerosis (CFSGS).. We describe a breast cancer patient who developed heavy proteinuria (protein/creatinine ratio 9.1) and nephrotic syndrome following treatment with oral ibandronate for 29 months. CFSGS was proven by biopsy. There was no improvement 1 month after ibandronate was discontinued. Prednisone and tacrolimus were started and she experienced a decreased in proteinuria.. In patient who develops ibandronate-associated CFSGS, proteinuria appears to be at least partially reversible with the treatment of prednisone and/or tacrolimus if the syndrome is recognized early and ibandronate is stopped.

Topics: Administration, Oral; Adult; Bone Density Conservation Agents; Bone Neoplasms; Breast Neoplasms; Diphosphonates; Female; Glomerulosclerosis, Focal Segmental; Humans; Ibandronic Acid; Prednisone; Proteinuria; Tacrolimus; Treatment Outcome

Tacrolimus is a calcineurin inhibitor that has been used to prevent allograft rejection after organ transplantation. We report the case of a living-donor liver transplant recipient with breast cancer who received adjuvant chemotherapy at an appropriate relative dose intensity in spite of a decrease in the trough blood concentration of tacrolimus. The patient was a woman in her 50s who had undergone living-donor liver transplantation because of primary biliary cirrhosis and received maintenance therapy consisting of tacrolimus. She was diagnosed as having locally advanced breast cancer(ER and HER2 positive). After surgery, we administered 4 courses of EC followed by weekly administration of paclitaxel plus trastuzumab. During chemotherapy, although the trough blood concentration of tacrolimus was slightly decreased, neither severe adverse event nor allograft rejection was observed. Recently, organ transplantation outcomes have significantly improved as a result of the progress of immunosuppressive agents. However, the development of malignancies after transplantation is a serious problem.

Topics: Breast Neoplasms; Chemotherapy, Adjuvant; Female; Humans; Liver Transplantation; Living Donors; Middle Aged; Tacrolimus

TGFβ-SMAD3 signaling is a major driving force for cancer metastasis, while BMP-SMAD1/5 signaling can counteract this response. Analysis of gene expression profiles revealed that an increased TGFβ-SMAD3 and a reduced BMP-SMAD1/5 targeted gene expression signature correlated with shortened distant metastasis free survival and overall survival of patients. At molecular levels, we discovered that TGFβ abolished BMP-induced SMAD1/5 activation in the highly-invasive breast cancer MDA-MB-231 cells, but to a less extent in the non-invasive cancer and normal breast cells. This suggests an inverse correlation between BMP signaling and invasiveness of tumor cells and TGFβ signaling acts in a double whammy fashion in driving cancer invasion and metastasis. Sustained ERK activation by TGFβ was specifically observed in MDA-MB-231 cells, and MEK inhibitor (MEKi) treatment restored BMP-SMAD1/5 signaling while not affecting SMAD2/3 activation. FK506 potently activated BMP, but not TGFβ signaling in breast cancer cells. MEKi or FK506 alone inhibited MDA-MB-231 extravasation in a zebrafish xenograft cancer model. Importantly, when administrated at suboptimal concentrations MEKi and FK506 strongly synergized in promoting BMP-SMAD1/5 signaling and inhibiting cancer cell extravasation. Furthermore, this combination of suboptimal concentrations treatment in a mouse tumor model resulted in real-time reduction of BMP-SMAD1/5 signaling in live tumors, and consequently potently inhibited tumor self-seeding, liver and bone metastasis, but not lung and brain metastasis. Mechanistically, it is the first time to identify BMP-SMAD1/5 signaling as an underlying molecular driver for organ-specific metastasis. Combining of MEKi and FK506, or their analogues, may be explored for clinical development of breast cancer.

Topics: Animals; Bone Morphogenetic Proteins; Breast Neoplasms; Butadienes; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Synergism; Female; Flavonoids; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; Mice; Neoplasm Metastasis; NIH 3T3 Cells; Nitriles; Organ Specificity; Protein Kinase Inhibitors; Signal Transduction; Tacrolimus; Xenograft Model Antitumor Assays; Zebrafish

Topics: Breast Neoplasms; Female; Humans; Immunosuppressive Agents; Patient Outcome Assessment; Prognosis; Tacrolimus; Transplantation

Breast cancer development and progression are influenced by insulin-like growth factor receptor 1 (IGF1R) and insulin receptor (InsR) signaling, which drive cancer phenotypes such as cell growth, proliferation, and migration. IGF1R and InsR form IGF1R/InsR hybrid receptors (HybRs) consisting of one molecule of IGF1R and one molecule of InsR. The specific signaling and functions of HybR are largely unknown, as HybR is activated by both IGF1 and insulin, and no cellular system expresses HybR in the absence of holo-IGF1R or holo-InsR. Here we studied the role of HybR by constructing inducible chimeric receptors and compared HybR signaling with that of holo-IGF1R and holo-InsR. We cloned chemically inducible chimeric IGF1R and InsR constructs consisting of the extracellular domains of the p75 nerve growth factor receptor fused to the intracellular β subunit of IGF1R or InsR and a dimerization domain. Dimerization with the drugs AP20187 or AP21967 allowed specific and independent activation of holo-IGF1R, holo-InsR, or HybR, resulting in activation of the PI3K pathway. Holo-IGF1R and HybR both promoted cell proliferation and glucose uptake, whereas holo-InsR only promoted glucose uptake, and only holo-IGF1R showed anti-apoptotic effects. We also found that the three receptors differentially regulated gene expression: holo-IGF1R and HybR up-regulated EGR3; holo-InsR specifically down-regulated JUN and BCL2L1; holo-InsR down-regulated but HybR up-regulated HK2; and HybR specifically up-regulated FHL2, ITGA6, and PCK2. Our findings suggest that, when expressed and activated in mammary epithelial cells, HybR acts in a manner similar to IGF1R and support further investigation of the role of HybR in breast cancer.

Topics: Animals; Breast Neoplasms; Cell Line, Transformed; Cell Proliferation; Female; Humans; Indicators and Reagents; Insulin; Insulin-Like Growth Factor I; Mammary Glands, Human; MCF-7 Cells; Mice; Models, Molecular; Neoplasm Proteins; Peptide Fragments; Protein Interaction Domains and Motifs; Protein Multimerization; Receptor, Insulin; Receptors, Somatomedin; Recombinant Fusion Proteins; Signal Transduction; Sirolimus; Tacrolimus

To report a case of local transmission of invasive lobular carcinoma from a donor to a recipient in a keratolimbal allograft after cessation of systemic immunosuppressive therapy.. This is a case report including the clinicopathologic findings. Sections of the donor breast tumor and recipient conjunctival lesions were stained with hematoxylin and eosin. Immunohistochemical studies were performed using pancytokeratin, CK7, CK20, CAM 5.2, CD138, TTF1, estrogen receptor, progesterone receptor, GATA-3, GCDFP-15, and mammaglobin. Polymerase chain reaction-based DNA profiling of tumor cells was performed.. Histopathologic examination revealed an infiltrate of atypical cells with large hyperchromatic nuclei consistent with carcinoma. Immunohistochemical analysis showed pancytokeratin, CK7, CAM 5.2, GATA-3, and estrogen receptor positivity and progesterone receptor absence, consistent with the previously determined phenotype of the donor's breast carcinoma. Results of polymerase chain reaction analysis were also consistent with the donor's tumor. After reduced dosing of tacrolimus and mycophenolate mofetil, 2 limbal tumors occurred in the recipient. The immunosuppressive treatment had been stopped completely before the appearance of the third lesion. The recipient had no history of malignancy, and she had routine screenings for breast cancer.. We report a case of donor-derived breast carcinoma in a keratolimbal allograft recipient. The grafted tissue harbored donor-derived tumor cells for more than 4 years after surgery even after systemic immunosuppression was discontinued. Although no similar reports of tumor transfer could be found in the literature, this case suggests the need for increased stringency in donor selection and heightened surveillance for such tumor transmission.

Topics: Aged; Allografts; Biomarkers; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Lobular; Conjunctival Neoplasms; Corneal Diseases; DNA Fingerprinting; Female; GATA3 Transcription Factor; Humans; Immunohistochemistry; Immunosuppressive Agents; Keratin-7; Keratins; Limbus Corneae; Mycophenolic Acid; Polymerase Chain Reaction; Receptors, Estrogen; Stem Cell Transplantation; Tacrolimus; Tissue Donors

With this study we aimed to research the effects of immunosuppressive drugs, their cumulative doses, and viral infections on development of malign tumors in patients who have undergone treatment for 5 years.. We examined 100 patients who underwent renal transplantation from 2004 to 2009. Patients had mycophenolate mofetil and steroid in addition to cyclosporine, sirolimus, or tacrolimus as immunosuppressive treatment. For malignancy screening, physical examination, radiologic and endoscopic screening were done, and immunosuppressive drugs and their cumulative doses, age, sex, body mass index (BMI), dialysis history, and viral infection history were investigated.. The mean age of patients was 42.03 ± 11.30 years. There were 1 colon cancer patient, 1 retroperitoneal liposarcoma, 1 renal oncocytoma, 3 Kaposi sarcoma patients treated with cyclosporine; in those treated with Tac there were 1 basal cell carcinoma, 1 Kaposi sarcoma, 2 thyroid carcinoma, 1 breast carcinoma, 1 bladder carcinoma, 1 renal cell carcinoma, and 1 colon carcinoma patients. The mean age of patients having carcinoma was statistically significant compared with those without cancer (P < .01). The prednisolone cumulative dose was significantly higher in carcinoma patients than in patients without carcinoma (P < .01).. The use of long-term chronic immunosuppressive therapy may increase the development of cancer. The risk of carcinoma increases with increasing drug dose and time period of the immunosuppressive drug. There was not a negative effect on cancer prevalence in patients with cyclosporine or tacrolimus. But the cumulative dose of steroids significantly increased malignancy occurence.

Topics: Adult; Breast Neoplasms; Carcinoma; Colonic Neoplasms; Cyclosporine; Early Detection of Cancer; Female; Humans; Immunosuppressive Agents; Kidney Transplantation; Male; Middle Aged; Mycophenolic Acid; Neoplasms; Retroperitoneal Neoplasms; Sarcoma, Kaposi; Sirolimus; Steroids; Tacrolimus; Thyroid Neoplasms; Time Factors; Urologic Neoplasms

SSEA-4, a sialyl-glycolipid, has been commonly used as a pluripotent human embryonic stem cell marker, and its expression is correlated with the metastasis of some malignant tumors. However, there is no in-depth functional study related to the receptor and the role of this glycolipid. Here, we report the identification of an SSEA-4-binding protein in a breast cancer cell line, MCF-7. By using affinity capture and glycan microarray techniques, the intracellular FK-506 binding protein 4 (FKBP4) was identified to bind directly to SSEA-4. The biological significance of SSEA-4/FKBP4 interaction was investigated.

Topics: Breast Neoplasms; Cell Line, Tumor; Chromatography, High Pressure Liquid; Female; Flow Cytometry; Humans; Mass Spectrometry; Microarray Analysis; Polyethylene Glycols; Polysaccharides; Protein Binding; Stage-Specific Embryonic Antigens; Tacrolimus; Tacrolimus Binding Proteins

Phyllodes tumor of the breast is a rare disease constituting 0.3-0.9% of all breast neoplasms. Occurring mainly in females aged 35 to 55 yr, the disease is especially rare among adolescent females. There is no published literature about de novo phyllodes tumor after liver transplantation. Here we describe a case of de novo phyllodes tumors in an adolescent female after liver transplantation from a living donor for Wilson disease.

Topics: Adolescent; Breast Neoplasms; Cyclosporine; Female; Hepatolenticular Degeneration; Humans; Immunosuppression Therapy; Immunosuppressive Agents; Liver Transplantation; Magnetic Resonance Imaging; Phyllodes Tumor; Recurrence; Remission Induction; Tacrolimus; Ultrasonography

Tacrolimus (FK506) is an immunosuppressive drug that binds to the immunophilin FKBPB12. The FK506-FKBP12 complex associates with calcineurin and inhibits its phosphatase activity, resulting in inhibition of nuclear translocation of nuclear factor of activated T-cells (NFAT). There is increasing data supporting a critical role of NFAT in mediating angiogenic responses stimulated by both vascular endothelial growth factor (VEGF) and a novel angiogenesis factor, secreted frizzled-related protein 2 (SFRP2). Since both VEGF and SFRP2 are expressed in breast carcinomas, we hypothesized that tacrolimus would inhibit breast carcinoma growth. Using IHC (IHC) with antibodies to FKBP12 on breast carcinomas we found that FKBP12 localizes to breast tumor vasculature. Treatment of MMTV-neu transgenic mice with tacrolimus (3 mg/kg i.p. daily) (n = 19) resulted in a 73% reduction in the growth rate for tacrolimus treated mice compared to control (n = 15), p = 0.003; which was associated with an 82% reduction in tumor microvascular density (p<0.001) by IHC. Tacrolimus (1 µM) inhibited SFRP2 induced endothelial tube formation by 71% (p = 0.005) and inhibited VEGF induced endothelial tube formation by 67% (p = 0.004). To show that NFATc3 is required for SFRP2 stimulated angiogenesis, NFATc3 was silenced with shRNA in endothelial cells. Sham transfected cells responded to SFRP2 stimulation in a tube formation assay with an increase in the number of branch points (p<0.003), however, cells transfected with shRNA to NFATc3 showed no increase in tube formation in response to SFRP2. This demonstrates that NFATc3 is required for SFRP2 induced tube formation, and tacrolimus inhibits angiogenesis in vitro and breast carcinoma growth in vivo. This provides a rationale for examining the therapeutic potential of tacrolimus at inhibiting breast carcinoma growth in humans.

Topics: Animals; beta Catenin; Breast Neoplasms; Calcineurin; Calcineurin Inhibitors; Cell Line, Tumor; Cell Movement; Endothelial Cells; Female; Gene Expression Regulation, Neoplastic; Humans; Membrane Proteins; Mice; Mice, Transgenic; Microvessels; Neovascularization, Pathologic; NFATC Transcription Factors; RNA Interference; Tacrolimus; Tacrolimus Binding Protein 1A; Vascular Endothelial Growth Factor A

Breast fibroadenomas may result from exposure to cyclosporine (CsA). The aim of this prospective study was to assess the reversibility of breast fibroadenomas following conversion from CsA to tacrolimus among a small cohort of female renal transplant recipients.. Following renal transplantation, fibroadenomas either developed or progressed in eight Caucasian female patients with CsA-based immunosuppression. These patients were enrolled in a pilot study assessing whether conversion from a CsA-based to a tacrolimus-based regimen prevented progression of breast disease or reversed existing lumps. Patients underwent a baseline visit in which we assessed the clinical history, number and dimension of fibroadenomas, graft function and hormonal profile (FSH prolactin, estradiol and progesterone). Twenty-one lumps were described in six patients; in addition, two patients had "grapes of fibroadenomas," of nondefinable numbers.. Patients underwent conversion to tacrolimus after a mean of 63.8 +/- 37.4 months after renal transplantation. Of the 21 clearly described lumps complete reversibility was observed for eight fibroadenomas. Other fibroadenomas either decreased in size or remained stable without further progression. These changes were reported within 1 year following conversion to tacrolimus.. A switch from CsA to tacrolimus was effective to prevent the progression of fibroadenomas. In female renal transplant recipients with CsA-based immunosuppression suffering from breast fibroadenomas, early CsA withdrawal may avoid the need for breast surgery.

Topics: Adult; Breast Neoplasms; Cyclosporine; Disease Progression; Estradiol; Female; Fibroadenoma; Follicle Stimulating Hormone; Humans; Immunosuppressive Agents; Kidney Transplantation; Mastectomy, Segmental; Middle Aged; Progesterone; Prolactin; Tacrolimus; Young Adult

Topics: Adult; Biopsy, Fine-Needle; Breast Neoplasms; Cyclosporine; Female; Fibroadenoma; Humans; Immunohistochemistry; Immunosuppressive Agents; Kidney Transplantation; Mastectomy; Risk Assessment; Sampling Studies; Tacrolimus

Oxygen-dependent radiosensitivity of tumour cells reflects direct oxidative damage to DNA, but non-nuclear mechanisms including signalling pathways may also contribute. Mitochondria are likely candidates because not only do they integrate signals from each of the main kinase pathways but mitochondrial kinases responsive to oxidative stress communicate to the rest of the cell. Using pharmacological and immunochemical methods, we tested the role of mitochondrial permeability transition (MPT) and the Bcl-2 proteins in oxygen-dependent radiosensitivity. Drug-treated or untreated cervical cancer HeLa, breast cancer MCF-7 and melanoma MeWo cell lines were irradiated at 6.2 Gy under normoxic and hypoxic conditions then allowed to proliferate for 7 days. The MPT blocker cyclosporin A (2 microM) strongly protected HeLa but not the other two lines against oxygen-dependent radiosensitivity. By contrast, bongkrekic acid (50 microM), which blocks MPT by targeting the adenine nucleotide transporter, had only marginal effect and calcineurin inhibitor FK-506 (0.1 microM) had none. Nor was evidence found for the modulation of oxygen-dependent radiosensitivity by Bax/Bcl-2 signalling, mitochondrial ATP-dependent potassium (mitoK(ATP)) channels or mitochondrial Ca(2+) uptake. In conclusion, calcineurin-independent protection by cyclosporin A suggests that MPT but not mitoK(ATP) or the mitochondrial apoptosis pathway plays a causal role in oxygen-dependent radiosensitivity of HeLa cells. Targeting MPT may therefore improve the effectiveness of radiotherapy in some solid tumours.

Topics: Anti-Bacterial Agents; bcl-2-Associated X Protein; Bongkrekic Acid; Breast Neoplasms; Cell Line, Tumor; Cyclosporine; Female; Humans; Immunosuppressive Agents; Melanoma; Mitochondria; Oxidative Stress; Radiation Tolerance; Tacrolimus; Uterine Cervical Neoplasms

Several studies have demonstrated significant interactions between immunosuppressants (e.g., cyclosporin A) and chemotherapeutic drugs that are BCRP substrates (e.g., irinotecan), resulting in increased bioavailability and reduced clearance of these agents. One possible mechanism underlying this observation is that the immunosuppressants modulate the pharmacokinetics of these drugs by inhibiting BCRP. Therefore, the aim of this study was to determine whether the immunosuppressants cyclosporin A, tacrolimus and sirolimus are inhibitors and/or substrates of BCRP.. First, the effect of the immunosuppressants on BCRP efflux activity in BCRP-expressing HEK cells was measured by flow cytometry.. Cyclosporin A, tacrolimus and sirolimus significantly inhibited BCRP-mediated efflux of pheophorbide A, mitoxantrone and BODIPY-prazosin. The EC(50) values of cyclosporin A, tacrolimus and sirolimus for inhibition of BCRP-mediated pheophorbide A efflux were 4.3 +/- 1.9 microM, 3.6 +/- 1.8 microM and 1.9 +/- 0.4 microM, respectively. Cyclosporin A, tacrolimus and sirolimus also effectively reversed resistance of HEK cells to topotecan and mitoxantrone conferred by BCRP. When direct efflux of cyclosporin A, tacrolimus and sirolimus was measured, these compounds were found not to be transported by BCRP. Consistent with this finding, BCRP did not confer resistance to the immunosuppressants in HEK cells.. These results indicate that cyclosporin A, tacrolimus and sirolimus are effective inhibitors but not substrates of BCRP. These findings could explain the altered pharmacokinetics of BCRP substrate drugs when co-administered with the immunosuppressants and suggest that pharmacokinetic modulation by the immunosuppressants may improve the therapeutic outcome of these drugs.

Topics: Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Breast Neoplasms; Cell Line, Tumor; Cell Survival; Cyclosporine; Drug Resistance, Neoplasm; Female; Flow Cytometry; Humans; Immunosuppressive Agents; Mitoxantrone; Neoplasm Proteins; Sirolimus; Substrate Specificity; Tacrolimus; Topotecan

FKBP51 and FKBP52 are large molecular weight FK506-binding immunophilins that have diverse biochemical functions. Best studied is the role that they play as components of steroid hormone receptors. Differential display and gene array screens have identified FKBP51 as a progestin-inducible gene. Here we demonstrate progestin enhancement of FKBP51 mRNA and protein in T-47D cells. FKBP51 mRNA and protein levels were increased 3-fold by 20 nM R5020. Induction of FKBP51 mRNA was unaffected by 1 micro g/ml cycloheximide but was blocked by the progestin receptor (PR) antagonist RU486 (1 micro M). Reporter plasmids containing 3.4 kb and 427 bp of 5'-flanking sequences of the human FKBP51 protein gene (FKBP5) exhibited regulation by progestin in T-47D cells. A construct containing 19 bp of upstream sequence demonstrated diminished basal activity and no stimulation by R5020. To test whether elevated FKBP51 affects progestin responsiveness, HepG2 cells were transfected with human FKBP51, PR, and mouse mammary tumor virus-luciferase plasmids, and treated with R5020 (0.03-10 nM). Expression of FKBP51 increased the EC(50) for PR transactivation by 3.2-fold. Expression of FKBP51 from squirrel monkey, a New World primate with naturally occurring progestin resistance, increased the EC(50) more dramatically (11.7-fold vs. control). Expression of FKBP51 bearing a double-point mutation in the tetratricopeptide repeat domain had no effect on PR transactivation. These results suggest that increased expression of FKBP51 by progestin may attenuate progestin responsiveness in hormone-conditioned cells. Furthermore, overexpression of FKBP51 in the squirrel monkey may be a contributing cause of progesterone resistance in this species.

Topics: Animals; Base Sequence; Breast Neoplasms; Carcinoma, Hepatocellular; Gene Expression; Humans; Liver Neoplasms; Molecular Sequence Data; Progesterone Congeners; Promegestone; Promoter Regions, Genetic; Saimiri; Sequence Homology, Nucleic Acid; Tacrolimus; Tacrolimus Binding Proteins; Transcription, Genetic; Tumor Cells, Cultured

The present study examines whether resistance to Cyclosporin A (CyA) and Tacrolimus (FK506) develops in T cells from individual patients and the role of P-glycoprotein 170 (P-gp) in mediating drug resistance. IC50s were established for CyA and FK506 in cell cultures from 46 renal allograft recipients. P-gp expression and functional activity were determined by flow cytometry. Mean ID50 for CyA was 29 microg/li (range 2.5-100) and for FK506 1.2 microg/li (range 0.085-5.5). The sensitivities to the two drugs were correlated (P = 0.0001). There was variation in the ratio of the ID50s depending on the drug used for treatment (P = 0.02). There was no difference in P-gp expression and functional activity in patients with sensitive or resistant cells. The data indicate an association between the sensitivities to CyA and FK506 and evidence of selective resistance to whichever drug was used. P-gp drug transport does not explain this variation.

Topics: Adult; Aged; ATP Binding Cassette Transporter, Subfamily B, Member 1; Breast Neoplasms; Calcineurin; Calcineurin Inhibitors; Carcinoma; Cells, Cultured; Cyclosporine; Cyclosporins; Drug Resistance; Drug Tolerance; Female; Humans; Immunosuppressive Agents; Kidney Transplantation; Male; Middle Aged; T-Lymphocytes; Tacrolimus; Tumor Cells, Cultured

The effects of immunosuppressants and inhibitors of specific calcium/calmodulin kinase (CaMK) of types II and IV on progestin/glucocorticosteroid-induced transcription were studied in two human stably transfected breast cancer T47D cell lines. The lines contain the chloramphenicol acetyl transferase (CAT) gene under control either of the mouse mammary tumor virus promoter (T47D-MMTV-CAT), or the minimal promoter containing five glucocorticosteroid/progestin hormone response elements [T47D-(GRE)5-CAT]. Progestin- and triamcinolone acetonide (TA)-induced CAT gene expression was inhibited in a dose-dependent manner in both lines by preincubation with rapamycin (Rap) and, to a lesser extent, with FK506, but not with cyclosporin A. CaMK II and/or IV inhibitors KN62 and KN93 also inhibited progestin- and TA-stimulated transcription in both lines. None of these drugs had any effect on basal transcription. The antagonist RU486 inhibited all the effects of both progestin and TA, suggesting that progesterone receptor (PR)-, as well as glucocorticosteroid receptor (GR)- mediated transactivation are targets of immunosuppressants and CaMKs in T47D cells. Indeed, Northern analysis showed that Rap, KN62, and, to a lesser degree, FK506 inhibited progestin stimulation of Cyclin D1 mRNA levels, but not those of the non-steroid-regulated glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene. Addition of Rap or KN62 after exposure of cells to progesterone agonist Org 2058 had no effect on induction of CAT activity. Taken together, these data indicate that Rap and FK506, as well as CaMK inhibitors, inhibit steroid-induced activities of exogenous, as well as of some endogenous, steroid receptor-regulated genes by a mechanism preceding hormone-induced receptor activation. Rap appeared to stabilize a 9S form of [3H]Org 2058-PR complexes isolated from T47D (GRE)5CAT cell nuclei. By contrast, the progesterone receptor (PR) was isolated from cells treated with KN62 as a 5S entity, undistinguishable from the 5S PR species extracted from cells treated with progestin only. The nuclear 9S-[3H]Org2058-PR resulting from cells exposed to Rap, contained, in addition to the heat shock proteins of 90 kDa and 70 kDa (hsp90 and hsp70), the FK506-binding immunophilin FKBP52 but not FKBP51, although the latter was part of unliganded PR heterocomplex associated with hsp90. These results suggest that Rap and KN62 act upon the PR by distinct mechanisms, with only Rap impeding progestin-induced PR t

Topics: Animals; Breast Neoplasms; Calcium-Calmodulin-Dependent Protein Kinases; Chloramphenicol O-Acetyltransferase; Enzyme Inhibitors; HSP70 Heat-Shock Proteins; HSP90 Heat-Shock Proteins; Humans; Immunosuppressive Agents; Macromolecular Substances; Mice; Polyenes; Promegestone; Receptors, Glucocorticoid; Receptors, Progesterone; RNA, Messenger; Sirolimus; Tacrolimus; Transcription, Genetic; Triamcinolone Acetonide; Tumor Cells, Cultured

T47D human breast carcinoma cells and the chicken oviduct were used to study the structure of the nonactivated progesterone receptor (PR) complex. Immunoprecipitation of PR (B form) from cytosol extracts was performed using monoclonal antibody PR6, a cross-reactive antibody prepared to chicken PR. Analysis of the PR complex by sodium dodecyl sulfate gels and Western immuno-blotting revealed the presence of several specific copurifying proteins. Consistent with previous reports, the two heat shock proteins, hsp90 and hsp70, were shown to be present. A third 59-kilodalton (kDa) protein observed previously was confirmed to be p59 (also called hsp56 or FKBP52), which has been shown to bind the immunosuppressant drug FK506. Two additional PR-associated proteins were observed that had not been previously recognized with human PR. These have molecular masses of 54-kDa and 23-kDa and have been shown by Western blotting to be related to the proteins p54 and p23 that are associated with chicken PR. P23 is a novel protein of unknown function and p54 or FKBP54 has been recently shown to be another FK506-binding protein related to p59. Finally, the cyclosporin A-binding protein, CyP-40, could be detected in isolated chicken PR complexes and in PR complexes that were reconstituted in vitro, but this protein was not detected in human PR complexes, which are less stable than chicken PR complexes in cytosol extracts. The functional significance of FK506 and cyclosporin A-binding proteins to hormone action was tested using a T47D cell line that contained a progestin reporter gene, MMTV-CAT. Treatment with cyclosporin A had no effect on the basal level of CAT expression, but it caused a dramatic increase in the sensitivity and magnitude of the response to the synthetic progestin, R5020. The enhanced response elicited by drug treatment was blocked by the antiprogestin RU486 indicating that this effect was receptor-mediated. While cyclosporin A enhanced progestin action in T47D cells, it inhibited a PR/reporter gene system in L cells. The drugs FK506 and rapamycin had no effect on progestin action in T47D cells, but they stimulated glucocorticoid action in T47D cells. Thus, the effects of these immunosuppressant drugs vary with the cell type and hormonal system that is tested. Whether these drug effects relate directly to the immunophilins bound in receptor complexes remains unknown.

Topics: Animals; Breast Neoplasms; Carcinoma; Carrier Proteins; Chickens; Cyclosporine; DNA-Binding Proteins; Gene Transfer Techniques; Heat-Shock Proteins; Humans; Immunosuppressive Agents; Mice; Receptor Aggregation; Receptors, Progesterone; Tacrolimus; Tacrolimus Binding Proteins; Tumor Cells, Cultured