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Biomedical subjects

Hideaki Yamana

Publications and source records attributed to Hideaki Yamana.

At least 19 recordsLinked to original sources

17Beta-estradiol induces down-regulation of Cap43/NDRG1/Drg-1, a putative differentiation-related and metastasis suppressor gene, in human breast cancer cells.

PURPOSE: Cap43 is known as a nickel- and calcium-inducible gene. In the present study, we examined whether 17beta-estradiol (E2) could affect the expression of Cap43 in breast cancer. EXPERIMENTAL DESIGN: Real-time PCR, immunoblotting, and immunocytochemistry were used to examine the expression of Cap43 and estrogen receptor-alpha (ER-alpha) in breast cancer cell lines. MDA-MB-231 and SK-BR-3 cell lines were transfected with ER-alpha cDNA to establish cells overexpressing ER-alpha. Immunohistochemistry was used to evaluate the expression of the Cap43 protein in breast cancer patients (n = 96), and the relationship between Cap43 expression and clinicopathologic findings was examined. RESULTS: Of the eight cell lines, four expressed higher levels of Cap43 with very low levels of ER-alpha, whereas the other four expressed lower levels of Cap43 with high ER-alpha levels. Treatment with E2 decreased the expression of Cap43 dose-dependently in ER-alpha-positive cell lines but not in ER-alpha-negative lines. Administration of antiestrogens, tamoxifen and ICI 182780, abrogated the E2-induced down-regulation of Cap43. Overexpression of ER-alpha in both ER-alpha-negative cell lines, SK-BR-3 and MDA-MB-231, resulted in down-regulation of Cap43. Immunostaining studies showed a significant correlation between Cap43 expression and the histologic grade of tumors (P = 0.0387). Furthermore, Cap43 expression was inversely correlated with the expression of ER-alpha (P = 0.0374). CONCLUSIONS: E2-induced down-regulation of Cap43 seems to be mediated through ER-alpha-dependent pathways in breast cancer cells both in culture and in patients. Cap43 has potential as a molecular marker to determine the therapeutic efficacy of antiestrogenic anticancer agents in breast cancer.

Cell Cycle Proteins↗

Long-term survival after three-field lymph-adenectomy for an adenocarcinoma in Barrett's esophagus with metastasis to Virchow's node.

Here, we report a case of long-term survival after resection of an adenocarcinoma in Barrett's esophagus with metastasis to Virchow's node. A 71-year-old woman was referred to our hospital with a tumor in the lower third of the thoracic esophagus, located just beneath the tracheal bifurcation because of an hiatal hernia. On admission, she had a palpable lymph node in Virchow's node. The esophageal tumor and this lymph node were biopsied. They were pathologically found to be an adenocarcinoma in the esophagus which had metastasised to the lymph node. She underwent transthoracic esophagectomy with three-field lymph node dissection. The pathological diagnosis was adenocarcinoma in Barrett's esophagus with the UICC stage classification of pT1, pN1, pM1-LYM, Stage IVB. She received postoperative chemotherapy of cisplatin combined with 5-fluorouracil. The patient is well without recurrence at 14 years to date after surgery. We recommend thoracoabdominal esophagectomy with three-field lymphadenectomy for an advanced carcinoma in the upper and middle thoracic esophagus regardless of histological types.

Abdomen↗

Activation of protein kinase C delta induces growth arrest in NPA thyroid cancer cells through extracellular signal-regulated kinase mitogen-activated protein kinase.

Protein kinase C (PKC) is a family of serine-threonine kinases that regulate many cell processes. To study the role of PKCdelta in thyroid cancer cells, we used a replication-deficient adenovirus (PKCdeltaAdV), to tightly control PKCdelta expression. In NPA cells, activation of wild-type (WT) PKCdelta with phorbol 12-myristate 13-acetate (PMA) induced an arrest in cell growth at G(1) phase, which was itself inhibited by the PKCdelta inhibitor rottlerin. Furthermore, overexpression of a dominant negative PKCdelta did not induce G(1) arrest. These findings strongly suggested that PKCdelta induced cell growth arrest in NPA cells. We investigated the mechanism of G1 arrest by examining G(1)-related proteins and mitogen-activated protein kinase (MAPK) by Western blotting. After activation of WTPKCdelta with PMA, cyclin E expression and retinoblastoma protein (Rb) phosphorylation decreased; the expression of p27(Kip1) increased and the phosphorylation of extracellular signal-regulated kinase (ERK) MAPK decreased. These results indicated that the activation of PKCdelta induced cell growth arrest in NPA cells, through an ERK MAPK-p27(Kip1)-cyclin E-pRb pathway. PKCdelta may therefore be an effective molecular target for novel therapy in thyroid cancer.

Adenoviridae↗

Characterization of IL-2-activated TILs and their use in intrapericardial immunotherapy in malignant pericardial effusion.

Pericardial effusion (PE) and cardiac tamponade caused by malignant pericarditis are critical conditions in cancer patients, which still lack a recommended protocol for their long-term management. Percutaneous pericardiocentesis and simple drainage are commonly performed as the initial treatment. The aims of this study were to investigate the presence of cytotoxic T lymphocytes (CTLs) in malignant PE and to determine the clinical response to administering autologous tumor-infiltrating lymphocytes (TILs) into the pericardial cavity. Initially, we identified human lymphocyte antigen class-I-restricted and tumor-specific CTLs within the interleukin-2 (IL-2)-activated TILs in PEs from four patients, on the basis of interferon-gamma production and lactate dehydrogenase-release assays. Clinically we observed favorable responses to the pericardial transfer of IL-2-activated autologous TILs in four patients: one male with advanced esophageal cancer, one female with recurrent lung cancer and two females with recurrent breast cancer, respectively. Autologous TILs from PEs were expanded in vitro with IL-2, characterized for CD3, CD4 and CD8 markers, checked for contamination and then infused into the patient's pericardial space through a catheter. This was repeated biweekly. After treatment, there were no signs of recurrence of PE in either case, as determined by radiography, echocardiography and computed tomography. The only adverse effects seen were grade 1 fevers. These results suggested that intrapericardial cellular immunotherapy with autologous TILs could be a safe and effective treatment for controlling malignant pericarditis with associated cardiac tamponade, and that tumor-specific CTLs present in malignant PE might be important for tumor rejection.

Aged↗

PKCdelta and MAPK mediate G(1) arrest induced by PMA in SKBR-3 breast cancer cells.

The effects of activating endogenous protein kinase C (PKC) on cell proliferation and the cell cycle were investigated by treating the breast cancer cell line SKBR-3 with phorbol 12-myristate 13 acetate (PMA). This inhibited cell growth in a concentration-dependent manner, causing a marked arrest of cells in G(1). Pre-treatment with GF109203X completely blocked the antiproliferative effect of PMA, and pre-treatment with the PKCdelta inhibitor rottlerin partially blocked it. Infecting SKBR-3 cells with an adenovirus vector containing wild-type PKCdelta, WTPKCdeltaAdV, had similar effects on PMA. Infecting the cells with a dominant-negative PKCdeltaAdV construct blocked the growth inhibition induced by PMA. Downstream of PKC, PMA treatment inhibited extracellular signal-regulated kinase mitogen-activated protein kinase phosphorylation, up-regulated c-jun NH(2)-terminal kinase phosphorylation, and inhibited retinoblastoma (Rb) phosphorylation. These results strongly implicated PKC (mainly PKCdelta) in the G(1) arrest induced by PMA and suggested PKC as a target for breast cancer treatment.

Breast Neoplasms↗

Cooperative cell-growth inhibition by combination treatment with ZD1839 (Iressa) and trastuzumab (Herceptin) in non-small-cell lung cancer.

An important recent advance in anticancer therapy was the development of molecular-targeting drugs, such as the epidermal growth-factor receptor (EGFR)-targeting drug ZD1839 (Iressa) and the HER2-trageting anti-HER2 monoclonal antibody trastuzumab (Herceptin). ZD1839 and trastuzumab are reported to improve the therapeutic efficacy of treatment for non-small-cell lung cancer (NSCLC) and breast cancer, respectively, although the effectiveness of either drug alone is not satisfactory. NSCLC cells often express both EGFR and HER2. We therefore investigated whether a combination of ZD1839 and trastuzumab had an additive or synergistic antitumor effect. In culture ZD1839 inhibited the growth of four NSCLC cell lines (A549, NCI-H23, NCI-H727, and NCI-H661) that expressed various levels of EGFR, HER2, HER3, and HER4. A significant cytotoxic effect was observed when ZD1839 was combined with trastuzumab in A549 cells. However, this combination had no apparent effect in NCI-H23 cells. Significant G(1)-phase arrest, increased p27 expression and decreased cyclin E or D1 levels were detected in A549 cells treated with ZD1839 and trastuzumab. No significant effects were detected in NCI-H23 cells examined. The combination treatment significantly inhibited the phosphorylation of EGFR, HER2, retinoblastoma, extracellular signal-regulated kinase-1/2, and protein kinase B/Akt in A549 cells, but not in NCI-H23 cells. Our results indicated that increased levels of constitutive EGFR/HER2 heterodimers were formed in A549 cells in the presence of ZD1839, whereas no heterodimer formation was detected in NCI-H23 cells. We therefore suggest that combination treatment with ZD1839 and trastuzumab might have improved therapeutic efficacy against NSCLC cells expressing both EGFR and HER2.

Antibodies, Monoclonal↗

Esophagectomy: is it necessary after chemoradiotherapy for a locally advanced T4 esophageal cancer? Prospective nonrandomized trial comparing chemoradiotherapy with surgery versus without surgery.

The need for surgery after chemoradiotherapy for a T4N0-1M0 squamous cell carcinoma in the thoracic esophagus was evaluated. A series of 53 patients were enrolled in this prospective nonrandomized trial from among 124 patients with an esophageal cancer assessed as T4 in Kurume University Hospital from 1994 to 2002. After the first chemoradiotherapy cycle, which consisted of radiotherapy in a total dosage of 36 Gy and chemotherapy using cisplatin (CDDP) and 5-fluorouracil (5FU), the patients each decided, after being informed of the efficacy of the chemoradiotherapy, whether to undergo surgery. All patients, including those who had undergone surgery and those who had not, later underwent a second chemoradiotherapy cycle consisting of radiotherapy in a total dosage of 24 Gy and chemotherapy using CDDP and 5FU, as far as practicable. Among the responders to the first chemoradiotherapy cycle, there was no significant difference in the long-term (5-year) survival rate between the 18 patients who underwent esophageal surgery and the 13 patients who did not (23% vs. 23%). Among the nonresponders, the 11 patients who underwent surgery showed a tendency toward longer survival than the five patients who had had no surgery. The nonresponders had 1- and 2-year survival rates of 64% and 33%, respectively. The corresponding rates for the 5 nonsurgical patients who completed the two chemoradiotherapy cycle were 20% and 20%, respectively. For a T4N0-1M0 squamous cell carcinoma in the thoracic esophagus, full-dosage chemoradiotherapy (definitive chemoradiotherapy) is preferred for responders to a half-dose of chemoradiotherapy as much as esophagectomy, whereas esophagectomy may be preferred for nonresponders.

Antineoplastic Combined Chemotherapy Protocols↗

Expired gas analysis during exercise testing pre-pneumonectomy.

PURPOSE: Expired gas analysis has enabled the successful prediction of postoperative complications in patients undergoing thoracic esophagectomy. We conducted this study to determine whether preoperative expired gas analysis during exercise testing can help identify patients at high risk of postoperative complications after pneumonectomy. METHODS: We measured the vital capacity, percent vital capacity, forced expiratory volume in 1.0 s, percent forced expiratory volume in 1.0 s, maximum oxygen uptake per minute, anaerobic threshold, arterial partial pressure of oxygen, and arterial partial pressure of carbon dioxide in 27 patients scheduled to undergo pneumonectomy. Group A consisted of 18 patients without postoperative cardiopulmonary complications and group B consisted of 9 patients with postoperative cardiopulmonary complications. We compared preoperative cardiopulmonary data between these two groups. RESULTS: Postoperative cardiopulmonary complications developed in 9 of the 27 patients (33.3%), 3 (11%) of whom died. The maximum oxygen uptake and the anaerobic threshold were significantly higher in group A than in group B (P < 0.05), whereas spirometric pulmonary function testing and arterial blood gas analysis showed no intergroup differences. CONCLUSION: Expired gas analysis during exercise testing can help identify patients at high risk of postoperative cardiopulmonary complications after pneumonectomy.

Adult↗

Advanced chemoresistant breast cancer responding to multidisciplinary treatment with hyperthermia, radiotherapy, and intraarterial infusion.

We employed multidisciplinary therapy, consisting of hyperthermia, radiotherapy, and intraarterial infusion, for a patient with progressive advanced breast cancer that was resistant to epirubicin hydrochloride and cyclophosphamide (EC) therapy as well as being resistant to docetaxel hydrate, and obtained a good therapeutic response. Because estrogen and progesterone receptors were both negative and HER2 was 3(+), administration of trastuzumab was started, and this patient has shown no signs of recurrence at 33 months after our treatment. The results suggested that our multidisciplinary therapy can be an effective method for the treatment of progressive breast cancer showing resistance to major chemotherapy agents such as anthracyclines and taxanes.

Antibodies, Monoclonal↗

Immunological evaluation of personalized peptide vaccination for patients with pancreatic cancer.

The prognosis of pancreatic cancer is extremely poor, and development of new treatment modalities is needed. One such treatment could be specific immunotherapy. To evaluate safety and immunological responses, we conducted a phase I study of personalized peptide vaccination for pancreatic cancer patients (n=11). Namely, pre-vaccination peripheral blood mononuclear cells were screened for their reactivity in vitro to each of 14 or 16 peptides in HLA-A24(+) or -A2(+) patients, and only the reactive peptides (maximum: 4) were vaccinated in vivo. This regimen was generally well tolerated, although inflammatory reactions at the injection site were observed in 7 patients. Delayed-type hypersensitivity to peptides used for vaccination was observed in 7 patients. Increased cellular and humoral immune responses to at least one of peptides used for vaccination were observed in the post-vaccination PBMCs and sera from 4 of 8 patients and 4 of 10 patients tested, respectively. The 6- and 12-month survival rates for patients who received >3 vaccinations (n=10) were 80% and 20%, respectively. Due to tolerability and capability of inducing specific immunity, further development of personalized peptide-based immunotherapy for pancreatic cancer patients is warranted.

Aged↗

Immunological evaluation of vaccination of peptides derived from epithelial cancer-related antigens in two patients with hematological malignancy.

Recent advances in tumor immunology have resulted in identification of many epithelial cancer-related antigens and peptides applicable to specific immunotherapy. We and others have reported that several epithelial cancer-related antigens are also expressed in hematological malignancies. Two patients with hematological malignancy (multiple myeloma and chronic lymphocytic leukemia) were vaccinated with peptides derived from epithelial cancer-related antigens to evaluate the immune responses to peptides under a personalized peptide vaccination regimen. There was no adverse event except for local skin reaction at the injection site. The peptide vaccination augmented both peptide-specific CTLs cytotoxic to hematological malignant cells in post-vaccination peripheral blood mononuclear cells and peptide-specific IgG in post-vaccination sera. A transient but obvious decrease of malignant cells was observed at the early phase of the vaccination in both cases. Vaccines consisting of peptides derived from epithelial cancer antigens safely increased anti-tumor cell activity in patients with hematological malignancies. These results may provide a scientific rationale in use of epithelial cancer-related antigens for specific immunotherapy to patients with hematological malignancies.

Aged↗

Antineoplaston induces G(1) arrest by PKCalpha and MAPK pathway in SKBR-3 breast cancer cells.

Antineoplastons such as A10 include naturally occurring peptides and amino acid derivatives that control the neoplastic growth of cells. The mechanism underlying this antitumor effect was investigated using the breast cancer cell line, SKRB-3. Cells treated with A10 were monitored for any changes in cell cycle, expression of protein kinase C (PKC), or intracellular signal transduction, particularly phos-phorylation of mitogen-activated protein kinase (MAPK). The A10 markedly inhibited SKBR-3 proliferation due to arrest in the G(1) phase. A10 down-regulated the expression of PKCalpha protein, resulting in inhibition of extracellular signal-regulated kinase (ERK) MAPK phosphorylation. This increased the expression of p16 and p21 protein, with resultant inhibition of Rb phosphorylation, leading to G(1) arrest. This study has defined a pathway in which A10 arrested SKBR-3 cells in the G(1) phase via PKCalpha and MAPK. Our findings indicate that the antineoplaston A10 antitumor effect could be utilized as an effective therapy for breast cancer patients.

Benzeneacetamides↗

[Combination immunotherapy using autologous tumor-stimulated lymphocytes and trastuzumab (Herceptin) for the patients with recurrent breast cancer].

PURPOSE: We report two patients with refractory recurrent breast cancer (HER2/neu: +) postoperatively, who had failed response to the available conventional chemotherapy of CAF (cyclophosphamide, adriamycin, 5-fluorouracil) and docetaxel, etc. They markedly responded to the combination immunotherapy using intraperitumoral injections of autologous tumor cell-stimulated T lymphocyte (AuTL) and trastuzumab (Herceptin), an anti-HER2 monoclonal antibody. METHODS: AuTLs were administrated directly into the recurrent tumor by intraperitumoral injections biweekly and trastuzumab was infused systemically every week. The treatments were repeated for 6 and 11 injections in the patients, respectively. The total administered T cells had reached to 3.8 x 10(9) and 6.4 x 10(9), respectively. The dosage of trastuzumab was 2 mg/kg in each patient. RESULTS: The carcinomatous pleural effusion had disappeared and was well controlled in patient 1 and a marked regression in injected fields in comparison to the size of the recurrent tumor before treatment was observed in patient 2. The tumor marker proteins (CEA, CA15-3, TPA) had also decreased significantly. The adverse effects of the immunotherapy were tolerable with grades 1-2 infusion reaction of fever, tachycardia and hypotension, but no cardiac dysfunction was observed. CONCLUSIONS: Clinical responses of recurrent breast cancer were observed in two patients after receiving the intra-peritumoral AuTL injection plus trastuzumab immunotherapy. These results showed that refractory recurrent breast cancer may be controlled effectively and safely by repeating the cellular immunotherapy combined with trastuzumab and suggested utility of combining these agents in clinical trial.

Adult↗

Humoral responses to peptides correlate with overall survival in advanced cancer patients vaccinated with peptides based on pre-existing, peptide-specific cellular responses.

PURPOSE: The aim of this study is to find a laboratory marker for overall survival in advanced cancer patients who were vaccinated with peptides based on pre-existing, peptide-specific CTL precursors in the circulation. EXPERIMENTAL DESIGN: A group of 113 patients with advanced cancer (28 colorectal, 22 prostate, 15 lung, 14 gastric, and 34 other cancers) was enrolled in a Phase I clinical study of peptide vaccination in which peptide-specific CTL precursors of prevaccination peripheral blood mononuclear cells were measured, followed by vaccination with these peptides (maximum of four). For cellular responses, pre and postvaccination (sixth) peripheral blood mononuclear cells were provided for measurement of both peptide-specific CTL precursors by IFN-gamma release assay and tumor reactivity by (51)Cr release assay. Delayed type hypersensitivity was also measured. For humoral response, pre and postvaccination (sixth) sera were provided for measurement of peptide-reactive IgG by an ELISA. RESULTS: The median survival time and 1-year survival rate of the total cases were 346 +/- 64.9 days and 44.6%, respectively, and those of patients vaccinated more than six times (n = 91) were 409 +/- 15 days and 54.4%, respectively. In these 91 patients, the overall survival of patients whose sera showed increased levels of peptide-reactive IgG (n = 60) was significantly more prolonged (P = 0.0003) than that of patients whose sera did not (n = 31), whereas none of cellular responses correlated with overall survival. CONCLUSIONS: Peptide-specific IgG in postvaccination sera could be a suitable laboratory maker for the prediction of prolonged survival in advanced cancer patients vaccinated with peptides based on pre-existing CTL precursors.

Adult↗

Preoperative spirometry versus expired gas analysis during exercise testing as predictors of cardiopulmonary complications after lung resection.

PURPOSE: As cardiopulmonary load increases with the amount of lung resected, to perform surgery safely it is important to be able to predict cardiopulmonary insufficiency. However, lung function testing with spirometry and blood gas analysis does not accurately measure cardiopulmonary reserve. We conducted this study to evaluate expired gas analysis during exercise testing for predicting postoperative complications after lung resection. METHODS: Expired gas analysis during exercise and spirometry were done 1 week preoperatively in 211 patients who underwent pulmonary resection for lung cancer. Patients were divided postoperatively according to whether cardiopulmonary complications were absent (group A) or present (group B). RESULTS: In group B there were more men than women (P < 0.01), and the mean age was greater (P < 0.05). There was no difference in disease stage, but more patients underwent pneumonectomy in group B than in group A ( P < 0.005). The results of expired gas analysis during exercise testing and of spirometry showed that maximum oxygen uptake/m(2) (P < 0.0005), anaerobic threshold/m(2) (P < 0.01), vital capacity (VC)/m(2) (P < 0.005), %VC (P < 0.0001), forced expiratory volume in 1 s (FEV(1.0))/m(2) (P < 0.0001), and FEV(1.0%) (P < 0.05) were lower in group B than in group A. CONCLUSIONS: The combination of expired gas analysis during exercise and conventional pulmonary function tests identified patients at risk for postoperative cardiopulmonary complications following pulmonary resection.

Aged↗

Phase I trial of patient-oriented vaccination in HLA-A2-positive patients with metastatic hormone-refractory prostate cancer.

To evaluate the safety and toxicity of peptide vaccination for patients with metastatic hormone-refractory prostate cancer (HRPC) based on pre-existing peptide-specific cytotoxic T-lymphocyte (CTL) precursors in the circulation, 10 patients positive for human leukocyte antigen (HLA)-A2 with metastatic HRPC were enrolled in a phase I study. Peptide-specific CTL-precursors reactive to 16 kinds of vaccine candidates in the pre-vaccination peripheral blood mononuclear cells (PBMCs) were measured, and patients were followed by vaccination with only positive peptides (up to 4 kinds of peptides). Serum prostate-specific antigen (PSA) levels were monitored regularly. The peptide vaccination was safe and well tolerated with no major adverse effects. The most common toxicities were dermatologic reactions at the injection site. Increased CTL response to peptides was observed in 4 of 10 patients. Anti-peptide IgG was also detected in post-vaccination sera of 7 of 10 patients. One patient showed the disappearance of a pelvic bone metastasis after five vaccinations. Three patients showed a decrease of serum PSA level from the baseline after the vaccination, but no patients showed a serum PSA level decrease of >/= 50%. The median survival duration of study patients was 22 months with follow-up from 3 to 27 months. We consider that the increase in cellular and humoral immune responses, and decrease in PSA level in some patients justify further development of peptide vaccination for metastatic HRPC patients.

Adenocarcinoma↗

Experimental gene therapy using p21Waf1 gene for esophageal squamous cell carcinoma by gene gun technology.

In our previous study, the proliferation rate of esophageal squamous cell carcinoma cell lines, which poorly expressed p21Waf1, was found to be regulated by p21Waf1 gene transfection using adenovirus vector. In the present study, in order to examine the effect of p21Waf1 gene therapy in esophageal cancer, we used gene gun technology, which proved to be a powerful method to introduce the p21Waf1 gene into esophageal cancer cells. p21Waf1 transfection to KE3 and YES2 cells (weakly expressed p21Waf1 protein cells) showed a high expression of p21Waf1 protein after applying this gene gun technique. In KE3 and YES2 cells, statistical significant growth inhibition was observed after p21Waf1 transfection compared with LacZ transfection (KE3, p=0.0009; YES2, p<0.0001). In in vivo transfection experiments, on day 14, the estimated volume of KE3 tumors subjected to p21Waf1 gene transfection was 95% in comparison with the pretreatment volume on day 0, while the volume of KE3 tumors subjected to LacZ gene therapy increased to 268%. On day 14, the estimated volume of YES2 tumors subjected to either p21Waf1 or LacZ gene therapy increased to 474 and 686%, respectively. In KE3 and YES2 cells, significant growth inhibition was observed after combination therapy using p21Waf1 transfection and anticancer drug 5-fluorouracil (5Fu) compared with 5Fu alone (KE3, p<0.0001; YES2, p<0.0001). In conclusion, p21Waf1 gene therapy using the gene gun technique significantly inhibited the low basal p21Waf1 expressed esophageal cancer cell growth in vitro and in vivo. Furthermore, p21Waf1 transfection strongly enhanced the effect of 5Fu suggesting that p21Waf1 may prove beneficial in chemotherapy combined with gene therapy using gene gun technology in patients with esophageal cancer who have a low level of p21Waf1 expressed tumor.

Animals↗

The role of nuclear Y-box binding protein 1 as a global marker in drug resistance.

Gene expression can be regulated by nuclear factors at the transcriptional level. Many such factors regulate MDR1 gene expression, but what are the sequence elements and transcription factors that control the basal and inducible expression of this gene? The general principles through which transcription factors participate in drug resistance are now beginning to be understood. Here, we review the factors involved in the transcriptional regulation of the MDR1 gene. In particular, we focus on the transcription factor Y-box binding protein 1 and discuss the possible links between Y-box binding protein 1 expression and drug resistance in cancer, which are mediated by the transmembrane P-glycoprotein or non-P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗