Home About us Contact
|
Home About us Contact | ||
|
|
||
Chemotherapeutic Treatment (chemotherapeutic + treatment)
Selected AbstractsOctamer 4 (Oct4) mediates chemotherapeutic drug resistance in liver cancer cells through a potential Oct4,AKT,ATP-binding cassette G2 pathway,HEPATOLOGY, Issue 2 2010Xiao Qi Wang Chemoresistance presents a major obstacle to the efficacy of chemotherapeutic treatment of cancers. Using chemotherapeutic drugs to select drug-resistant cancer cells in hepatocellular carcinoma (HCC) and several other cancer cell lines, we demonstrate that chemoresistant cells displayed cancer stem cell features, such as increased self-renewal ability, cell motility, multiple drug resistance, and tumorigenicity. Octamer 4 (Oct4) messenger RNA (mRNA) levels were dramatically increased in chemoresistant cancer cells due to DNA demethylation regulation of Oct4. By functional study, Oct4 overexpression enhanced whereas Oct4 knockdown reduced liver cancer cell resistance to chemotherapeutic drugs in vitro and in xenograft tumors. It is known that the Oct4-TCL1-AKT pathway acts on embryonic stem cells and cancer stem cells in cell proliferation through inhibition of apoptosis. We further demonstrate that Oct4 overexpression induced activation of TCL1, AKT, and ABCG2 to mediate chemoresistance, which can be overcome by addition of the PI3K/AKT inhibitor; therefore, a direct pathway of Oct4-TCL1-AKT-ABCG2 or a combination of Oct4-TCL1-AKT with the AKT-ABCG2 pathway could be a potential new mechanism involved in liver cancer cell chemoresistance. Moreover, the clinical significance of the Oct4-AKT-ABCG2 pathway can be demonstrated in HCC patients, with a strong correlation of expression patterns in human HCC tumors. The role of the Oct4-AKT-ABCG2 axis in cancer cell chemoresistant machinery suggests that AKT pathway inhibition (PI3K inhibitors) not only inhibits cancer cell proliferation, but may also enhance chemosensitivity by target potential chemoresistant cells. Conclusion: Oct4, a transcriptional factor of pluripotent cells, can mediate chemoresistance through a potential Oct4-AKT-ABCG2 pathway. (HEPATOLOGY 2010;) [source] Expression of multidrug resistance-associated protein 1 in invasive ovarian carcinoma: implication for prognosisHISTOPATHOLOGY, Issue 6 2009Areeg Faggad Aims:, Multidrug resistance is a major impediment in chemotherapeutic treatment of ovarian carcinoma patients. The aim of this study was to investigate the expression of multidrug resistance-associated protein 1 (MRP1) and to assess the possible associations with clinicopathological variables and patient outcome in primary ovarian carcinoma. Methods and results:, Tumour specimens from 129 patients were obtained before chemotherapy and analysed by immunohistochemistry on tissue microarrays, and by real-time reverse transcriptase-polymerase chain reaction on RNA extracted from formalin-fixed paraffin-embedded tissue specimens using a new technique. Significantly increased MRP1 protein expression was observed in high-grade tumours (P = 0.005) and advanced International Federation of Gynaecology and Obstetrics stages (P = 0.036). On univariate Kaplan,Meier analysis, patients with higher expression of MRP1 protein had significantly decreased overall survival (P = 0.006). On multivariate Cox regression analysis, MRP1 protein expression retained its significance as an independent negative prognostic marker for overall survival (hazard ratio = 6.52, P = 0.003). Furthermore, MRP1 expression correlated with topoisomerase II, expression both at mRNA and protein level (P < 0.001 and P = 0.023, respectively). Conclusion:, In summary, in patients with primary ovarian cancer, overexpression of MRP1 is an adverse marker for patient outcome and cancer aggressiveness. Our data provide a translational basis for further clinical studies on the predictive value of MRP1 expression for response to chemotherapy. [source] Cardiotoxicity of doxorubicin/paclitaxel combination in rats: Effect of sequence and timing of administrationJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 2 2004Sherif Y. Saad Abstract The higher incidence of cardiotoxicity of doxorubicin (DOX)/paclitaxel (PTX) combination compared with DOX alone remains to be a major obstacle against effective chemotherapeutic treatment. We investigated the effect of sequence and time interval between administration of both drugs on the severity of cardiotoxicity of the combination. Male Wistar rats were divided into seven groups. DOX was administeded intraperitoneally (ip) at a single dose of 5 mg kg,1 every other 2 days, 2 doses per week for a total cumulative dose of 20 mg kg,1. PTX was administered by an ip route at a dose of 20 mg kg,1 every other 2 days. Both drugs were injected either alone or sequentially in combination. In one case, DOX preceded PTX by 30 min and 24 h and in the other case, PTX preceded DOX by 30 min and 24 h. Cardiotoxicity was evaluated by both biochemical and histopathological examination, 48 h after the last DOX dose. DOX-induced cardiotoxicity was manifested by abnormal biochemical changes including marked increases in serum creatine phosphokinase isoenzyme (CK-MB), lactate dehydrogenase (LDH), glutathione peroxidase (GSH-Px), and aspartate aminotransferase (AST) activity levels. Myocardial tissue from DOX-treated rats showed significant increases in malondialdehyde (MDA) production and total nitrate/nitrite (NOx) levels, parallel with depletion of "endogenous antioxidant reserve," including GSH contents and GSH-Px activity level. PTX treatment produced significant changes in the biochemical parameters measured by a lower magnitude than those changes produced by DOX alone. Combination of both drugs resulted in aggravation of DOX-induced cardiotoxicity regardless the sequence and time interval between administration of either drug. Administration of PTX 30 min and 24 h after DOX treatment showed exaggeration of combination-induced cardiotoxicity compared with the reverse sequence. This exacerbation was manifested by much more pronounced changes in serum and cardiac tissue parameters measured. Histopathological examination of ventricles of rat's heart revealed that DOX treatment produced myo-cytolysis and myocardial necrosis. Administration of PTX following DOX treatment showed extensive myocardial necrosis compared with those rats treated with either DOX alone or the reverse sequence of administration. Moreover, rats treated with PTX 24 h after DOX treatment showed exaggeration of the combination-induced cardiotoxicity. In conclusion, PTX might synergistically aggravate DOX-induced cardiotoxicity. The effect might be much more pronounced with those rats treated with PTX 24 h after DOX treatment. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:78,86, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20012 [source] Differential expression of insulin-like growth factor binding protein-5 in pancreatic adenocarcinomas: Identification using DNA microarrayMOLECULAR CARCINOGENESIS, Issue 11 2006Sarah K. Johnson Abstract Pancreatic ductal adenocarcinoma (PDAC) is characterized by its aggressiveness and resistance to both radiation and chemotherapeutic treatment. To better understand the molecular pathogenesis of pancreatic cancer, DNA array technology was employed to identify genes differentially expressed in pancreatic tumors when compared to non-malignant pancreatic tissues. RNA isolated from 11 PDACs and 14 non-malignant bulk pancreatic duct specimens was used to probe Affymetrix U95A DNA arrays. Genes that displayed at least a fourfold differential expression were identified and real-time quantitative PCR was used to verify the differential expression of selected upregulated genes. Interrogation of the DNA array revealed that 73 genes were upregulated in PDACs and 77 genes were downregulated. The majority of the 150 genes identified have not been previously reported to be differentially expressed in pancreatic tumors, although a number of the upregulated transcripts have been reported previously. Immunohistochemistry was used to correlate calponin and insulin-like growth factor binding protein-5 (IGFBP-5) RNA levels with protein expression in PDACs and revealed peritumoral calponin staining in the reactive stroma and intense focal staining of islets cells expressing IGFBP-5 at the edge of tumors; thus implicating the interplay of various cell types to promote neoplastic cell growth within pancreatic carcinomas. As a potential modulator of cell proliferation, the overexpression of IGFBP-5 may, therefore, play a significant role in the malignant transformation of normal pancreatic epithelial cells. © 2006 Wiley-Liss, Inc. [source] Oral mucositis in acute lymphoblastic leukaemia: analysis of 169 paediatric patientsORAL DISEASES, Issue 8 2008SLC Figliolia Chemotherapy-induced oral mucositis is a frequent therapeutic challenge in cancer patients. The purpose of this retrospective study was to estimate the prevalence and risk factors of oral mucositis in 169 acute lymphoblastic leukaemia (ALL) patients treated according to different chemotherapeutic trials at the Darcy Vargas Children's Hospital from 1994 to 2005. Demographic data, clinical history, chemotherapeutic treatment and patients' follow-up were recorded. The association of oral mucositis with age, gender, leucocyte counts at diagnosis and treatment was assessed by the chi-squared test and multivariate regression analysis. Seventy-seven ALL patients (46%) developed oral mucositis during the treatment. Patient age (P = 0.33), gender (P = 0.08) and leucocyte counts at diagnosis (P = 0.34) showed no correlation with the occurrence of oral mucositis. Multivariate regression analysis showed a significant risk for oral mucositis (P = 0.009) for ALL patients treated according to the ALL-BFM-95 protocol. These results strongly suggest the greater stomatotoxic effect of the ALL-BFM-95 trial when compared with Brazilian trials. We concluded that chemotherapy-induced oral mucositis should be systematically analysed prospectively in specialized centres for ALL treatment to establish the degree of toxicity of chemotherapeutic drugs and to improve the quality of life of patients based on more effective therapeutic and prophylactic approaches for prevention of its occurrence. [source] Antitumor activity and mechanism of action of the iron chelator, Dp44mT, against leukemic cells,AMERICAN JOURNAL OF HEMATOLOGY, Issue 3 2009Egarit Noulsri Iron chelators have been reported to induce apoptosis and cell cycle arrest in cancer cells. Recent studies suggest broad and selective antitumor activity of the new iron chelator, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT; Whitnall et al., Proc Natl Acad Sci USA 2006;103:14901,14906). However, little is known concerning its effects on hematological malignancies. Using acute leukemia cells, the effect of Dp44mT on apoptosis, cell cycle, caspase-3 activation, and mitochondrial trans-membrane potential has been examined by flow cytometry. Dp44mT acted to induce a G1/S arrest in NB4 promyelocytic leukemia cells at low concentrations (0.5,2.5 ,M), being far more effective than the clinically used chelator, desferrioxamine (DFO). Moreover, Dp44mT induced apoptosis of NB4 cells in a dose- and time-dependent manner with markedly less effect on nonproliferating cells. The apoptosis-inducing activity of Dp44mT was significantly more effective than DFO. Furthermore, this study also showed that Dp44mT had broad activity, inducing apoptosis in several types of acute leukemia and also multiple myeloma cell lines. Additional studies examining the cytotoxic mechanisms of Dp44mT showed that a reduction in the mitochondrial trans-membrane potential and caspase-3 activation could be involved in the mechanism of apoptosis. Our results suggest that Dp44mT possesses potential as an effective cytotoxic agent for the chemotherapeutic treatment of acute leukemia. Am. J. Hematol. 2009. © 2008 Wiley-Liss, Inc. [source] You can win by losing: p53 mutations in rhabdomyosarcomas,THE JOURNAL OF PATHOLOGY, Issue 2 2010Sean M Post Abstract Rhabdomyosarcomas are soft tissue sarcomas of mesenchymal origin. Unlike rhabdomyosarcomas observed in paediatric patients which typically respond well to chemotherapeutic treatment, adults generally present with pleomorphic rhabdomyosarcomas that are typically associated with poor prognosis. Therefore, understanding the molecular biology that gives rise to pleomorphic rhabdomyosarcomas is critical. In this issue of The Journal of Pathology, Doyle and colleagues have generated elegant tissue-specific Cre/loxP-dependent mouse models that mimic pleomorphic rhabdomyosarcoma development in humans. In this report, the authors employed KRasG12V -expressing mouse models that concomitantly either express mutant p53 (p53R172H) or have deleted the p53 gene. Mice that express mutant p53 have decreased survival with development of aggressive metastases as compared to mice that have simply lost wild-type p53. The data presented herein provide the first in vivo evidence that in rhabdomyosarcomas, expression of mutant p53 results in a more aggressive p53R172H-dependent gain-of-function phenotype. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Invited Commentary for Doyle B et al.p53 mutation and loss have different effects on tumourigenesis in a novel mouse model of pleomorphic rhabdomyosarcoma. Journal of Pathology, 2010; 222: 129,137. [source] Low-dose mithramycin exerts its anticancer effect via the p53 signaling pathway and synergizes with nutlin-3 in gynecologic cancersCANCER SCIENCE, Issue 6 2010Tatsuhiro Ohgami MDM2 is a direct negative regulator of p53. The p53-independent mdm2-P1 and p53-dependent mdm2-P2 promoters have been recently shown to harbor Sp1 binding sites. Mithramycin, an inhibitor of Sp1 DNA binding, has been used clinically to treat hypercalcemia and some types of neoplastic disorders. In this study, we investigated the mechanisms behind the anticancer effect of mithramycin. In gynecologic cancer cells expressing wild-type p53, mithramycin stabilized p53 and increased the expression of the p53 downstream target genes PUMA and p21, arrested the cell cycle, and induced apoptosis. This activation of the p53 signaling pathway was a specific effect of MTH at concentrations <50 nm. Mithramycin temporally decreased transcription of both the mdm2-P1 and -P2 promoters. This was followed by a subsequent increase of mdm2-P2 promoter activity by activated p53. Up-regulated MDM2 was in its active form, and consequently attenuated p53 activity. Although mithramycin activated p53 and suppressed the growth of human gynecologic cancer cell xenografts in mice, this was accompanied with a secondary up-regulation of MDM2. Combined treatment with mithramycin and nutlin-3, a drug that inhibits MDM2,p53 interaction, overcame a secondary up-regulation of MDM2 and synergistically inhibited cancer cell growth by inducing apoptosis through activation of the p53 signaling pathway. These observations provide a better understanding of the mechanisms of mithramycin activity, and suggest a potential role for combining mithramycin and nutlin-3 as a chemotherapeutic treatment for gynecologic cancers. (Cancer Sci 2010; 101: 1387,1395) [source] Epithelial,mesenchymal transition in cancer development and its clinical significanceCANCER SCIENCE, Issue 2 2010Masaaki Iwatsuki The epithelial,mesenchymal transition (EMT) plays a critical role in embryonic development. EMT is also involved in cancer progression and metastasis and it is probable that a common molecular mechanism is shared by these processes. Cancer cells undergoing EMT can acquire invasive properties and enter the surrounding stroma, resulting in the creation of a favorable microenvironment for cancer progression and metastasis. Furthermore, the acquisition of EMT features has been associated with chemoresistance which could give rise to recurrence and metastasis after standard chemotherapeutic treatment. Thus, EMT could be closely involved in carcinogenesis, invasion, metastasis, recurrence, and chemoresistance. Research into EMT and its role in cancer pathogenesis has progressed rapidly and it is now hypothesized that novel concepts such as cancer stem cells and microRNA could be involved in EMT. However, the involvement of EMT varies greatly among cancer types, and much remains to be learned. In this review, we present recent findings regarding the involvement of EMT in cancer progression and metastasis and provide a perspective from clinical and translational viewpoints. (Cancer Sci 2009) [source] Lethal double infection with Acremonium strictum and Aspergillus fumigatus during induction chemotherapy in a child with ALLPEDIATRIC BLOOD & CANCER, Issue 6 2007J. L. Foell MD Abstract Fungal infections are a major cause of morbidity and mortality in patients during chemotherapeutic treatments and malignant hematologic disease. We present a case of a double fungal infection with disseminated Acremoniumstrictum (A. strictum) and pulmonary Aspergillus fumigatus (A. fumigatus) and its rapid clinical course. A 17-year-old boy with prolonged neutropenia developed a disseminated fungal infection during induction chemotherapy of his acute lymphoblastic leukemia. The infection was rapidly lethal despite neutrophil recovery and early antifungal combination therapy with amphotericin B and caspofungin. Since there are only a few reports about invasive Acremonium infections, we present this case with regard to differences in the clinic pathologic features of Aspergillosis and other opportunistic fungal infections due to Fusarium or Acremonium species. Pediatr Blood Cancer 2007;49:858,861. © 2006 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||