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Tumor Regression (tumor + regression)
Selected AbstractsReduction rate of lymph node metastasis as a significant prognostic factor in esophageal cancer patients treated with neoadjuvant chemoradiation therapyDISEASES OF THE ESOPHAGUS, Issue 2 2007S. Aiko SUMMARY., Tumor regression is used widely as a measure of tumor response following radiation therapy or chemoradiation therapy (CRT). In cases of esophageal cancer, a different pattern of tumor shrinkage is often observed between primary tumors and metastatic lymph nodes (MLNs). Regression of MLNs surrounded by normal tissue may be a more direct measure of the response to CRT than regression of a primary tumor as exfoliative mechanical clearance does not participate in shrinkage of MLNs. In this study we evaluated the significance of the reduction rate (RR) of MLNs as a prognostic factor in esophageal cancer patients treated with neoadjuvant CRT. Forty-two patients with marked MLNs were selected from 93 patients with esophageal carcinoma who had received neoadjuvant CRT. The RRs of the primary tumor and the MLNs were calculated from computed tomography scans. In 20 patients, surgical resection was carried out following CRT. Univariate analysis was used to determine which of the following variables were related to survival: size of the primary tumor and MLNs; RRs of both lesions; degree of lymph node (LN) metastasis; clinical stage; and surgical resection. Multivariate analysis was then performed to assess the prognostic relevance of each variable. The primary tumor was larger than the MLNs in 69% of patients before CRT and in 40% of patients after CRT. In 79% of the patients, the RR of the primary tumor was greater than the RR of the MLNs. The results of the univariate analyses showed that a high RR of the MLNs and surgical resection after CRT were associated with significantly improved survival. The multivariate analysis demonstrated that the RR of MLNs had the strongest influence on survival. The RR of LN metastasis should be evaluated as an important prognostic predictor in patients with marked LN metastasis of esophageal cancer treated with CRT. [source] EGFR tyrosine kinase inhibition radiosensitizes and induces apoptosis in malignant glioma and childhood ependymoma xenograftsINTERNATIONAL JOURNAL OF CANCER, Issue 1 2008Birgit Geoerger Abstract Malignant gliomas and childhood ependymomas have a high rate of treatment failure. Epidermal growth factor receptor (EGFR) activation has been implicated in the tumorigenesis and radioresistance of many cancers, including brain tumors. Therefore, combining EGFR targeting with irradiation is a potentially attractive therapeutic option. We evaluated the tyrosine kinase inhibitor gefitinib for its antitumor activity and potential to radio-sensitize in vivo in two xenograft models: an EGFR amplified glioma and an EGFR expressing ependymoma, both derived from primary tumors. When administered at 100 mg/kg for 5 consecutive days, gefitinib-induced partial tumor regression in all treated EGFR amplified IGRG88 glioma xenografts. The addition of 1 Gy of irradiation prior to gefitinib administration resulted in 5 complete and 4 partial regressions for the 9 treated tumors as well as a significant tumor growth delay of 33 days for the combined treatment compared to 19 days for each therapy alone, suggesting additive antitumor activity. Tumor regression was associated with inhibition of AKT and MAPK pathways by gefitinib. In contrast, the ependymoma IGREP83 was sensitive to irradiation, but remained resistant to gefitinib. Combined treatment was associated with inhibition of radiation-induced MAPK phosphorylation and significant induction of apoptotic cell death though radiation-induced AKT phosphorylation was maintained. Depending on the scheduling of both therapies, a trend towards superior antitumor activity was observed with combined treatment. Thus, EGFR targeting through tyrosine kinase inhibition appears to be a promising new approach in the treatment of EGFR-driven glioma, particularly in combination with radiation therapy. © 2008 Wiley-Liss, Inc. [source] Mucosa-associated lymphoid tissue lymphoma: Molecular pathogenesis and clinicopathological significancePATHOLOGY INTERNATIONAL, Issue 8 2007Hiroshi Inagaki Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade tumor closely associated with chronic inflammation such as that of Helicobacter pylori gastritis, Sjogren's syndrome, and Hashimoto's thyroiditis. Tumor regression by H. pylori eradication alone is well known in gastric MALT lymphoma, but some tumors occur in the absence of pre-existing chronic inflammation. The understanding of MALT lymphoma biology has significantly improved, and recurrent cytogenetic alterations have been detected. These include the trisomies 3 and 18, and the translocations t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). At least some of these alterations result in the constitutive activation of the nuclear factor (NF)-,B pathway, and may exert anti-apoptotic action. Apoptosis inhibitor 2,MALT lymphoma-associated translocation 1 (API12 - MALT1) fusion, resulting from t(11;18)(q21;q21), is specific to, and is the most common in, MALT lymphomas, and its clinicopathological significance has been studied extensively. The focus of the present review is on the recent progress made in elucidating MALT lymphomagenesis and its clinicopathological impact, especially in terms of the effect of API2-MALT1 fusion on this unique tumor. [source] Resection surgery with neoadjuvant chemoradiotherapy improves outcomes of patients with T4 esophageal carcinomaDISEASES OF THE ESOPHAGUS, Issue 2 2003T. Noguchi SUMMARY The prognosis of patients with T4 esophageal carcinoma is poor, and thus an effective treatment needs to be established. The present study assessed the effect of chemoradiotherapy (CRT), postoperative morbidity and mortality, and survival time in 41 patients with T4 esophageal carcinoma. Of these, 24 received CRT followed by surgery (group A) and the remaining 17 were treated with CRT alone (group B). Postoperative complications in group A were compared with 251 patients (group C) who underwent surgery without CRT during the same period. Postoperative complications were more frequent in group A than group C (29.2%vs 8.4%, P < 0.05). The overall median survival of group A was statistically longer than that of group B (13.8 months and 3.3 months respectively, P < 0.001). Complete histologic response (grade 3) was documented in 4 group A patients (16.7%). The overall median survival of grade 3 patients was statistically longer than the rest of group A (38.9 months vs 8.8 months, P < 0.05). The data confirm that chemoradiotherapy creates tumor regression in some patients and allows resection surgery in T4 esophageal carcinoma. Moreover, surgery with CRT confers a survival advantage in T4 esophageal carcinoma. [source] LBY135, a novel anti-DR5 agonistic antibody induces tumor cell,specific cytotoxic activity in human colon tumor cell lines and xenografts,DRUG DEVELOPMENT RESEARCH, Issue 2 2008Jing Li Abstract TRAIL (TNF-related apoptosis-inducing ligand) induces apoptosis on binding to DR4 and DR5 receptors on the surface of tumor cells. These receptors are of particular interest in the development of cancer therapeutics as they preferentially mediate tumor cell apoptosis. We have generated a chimeric anti-DR5 agonistic antibody, LBY135, from its murine parental antibody, LCR211, identified using hybridoma technology. Both LCR211 and LBY135 specifically bind to DR5 with nanomolar affinity, mimic TRAIL to induce cell death in tumor cells, and have little effect on non-transformed cells in vitro. The anti-DR5 antibody reduced viability in 45% of a panel of 40 human colon cancer cell lines with IC50 values of 20,nM or less. In vivo, using human colorectal tumor xenograft mouse models, LCR211 induced tumor regression and showed enhanced efficacy when combined with 5-FU. Both in vitro evaluation of ADCC (antibody-dependent cell-mediated cytotoxicity) and CDC (complement-dependent cytotoxicity), and in vivo studies using a non-functional DR5 specific antibody or SCID-Beige mice, suggested ADCC and CDC are unlikely to be the mechanism to ablate tumors in vivo. LBY135 and LCR211 appear to mediate cell death and tumor regression mainly through apoptosis, as demonstrated by the activation of caspase 3, caspase 8, M30, and TUNEL assay. In addition, the discovery of synergy between cross-linked LBY135 and TRAIL not only revealed the unique epitope of LBY135, but also demonstrated an additional mechanism of action for LBY135 in vivo. LBY135 demonstrates promise as a novel therapeutic for cancer treatment and is currently in Phase I clinical trials. Drug Dev Res 69: 69,82, 2008. © 2008 Wiley-Liss, Inc. [source] CD44 variant isoform v10 is expressed on tumor-infiltrating lymphocytes and mediates hyaluronan-independent heterotypic cell,cell adhesion to melanoma cellsEXPERIMENTAL DERMATOLOGY, Issue 2 2003T. K. Weimann Abstract: CD44 is a family of cell-surface receptors on human lymphocytes that act as co-stimulatory molecules leading to the induction of effector functions in T cells. We have analyzed primary cutaneous malignant melanomas with clinical and histologic signs of tumor regression using immunohistochemistry and observed the predominant expression of the CD44 variant isoform v10 on CD3 CD4/CD8 co-expressing tumor-infiltrating lymphocytes (TIL). We further analyzed the role of CD44v10 in adhesion of lymphocytes to human melanoma cells. In contrast to CD44, lymphatic cells, CD44v10+ lymphatic cells strongly bound to cultured human melanoma cells and to frozen tissue samples of melanomas. Antibody blocking studies revealed a hyaluronan-, integrin-, and selectin-independent pathway of adhesion. Furthermore, CD44v10+ lymphatic cells exhibited significantly higher invasiveness in three-dimensional collagen matrices as compared with CD44H+ and CD44-negative lymphocytes. These results indicate that expression of CD44v10 on TIL may mediate adhesion to melanoma cells and result in gain of novel invasive properties. [source] Engineered measles virus as a novel oncolytic viral therapy system for hepatocellular carcinoma,HEPATOLOGY, Issue 6 2006Boris Blechacz The oncolytic measles virus Edmonston strain (MV-Edm), a nonpathogenic virus targeting cells expressing abundant CD46, selectively destroys neoplastic tissue. Clinical development of MV-Edm would benefit from noninvasive monitoring strategies to determine the speed and extent of the spread of the virus in treated patients and the location of virus-infected cells. We evaluated recombinant MV-Edm expressing carcinoembryonic antigen (CEA) or the human sodium iodide symporter (hNIS) for oncolytic potential in hepatocellular carcinoma (HCC) and efficiency in tracking viruses in vivo by noninvasive monitoring. CD46 expression in human HCC and primary hepatocytes was assessed by flow cytometry and immunohistochemistry. Infectivity, syncytium formation, and cytotoxicity of recombinant MV-Edm in HCC cell lines were evaluated by fluorescence microscopy, crystal violet staining, and the MTS assay. Transgene expression in HCC cell lines after infection with recombinant MV-Edm in vitro and in vivo was assessed by CEA concentration, 125I-uptake, and 123I-imaging studies. Toxicology studies were performed in IfnarKO×CD46 transgenic mice. The CD46 receptor was highly expressed in HCC compared to nonmalignant hepatic tissue. Recombinant MV-Edm efficiently infected HCC cell lines, resulting in extensive syncytium formation followed by cell death. Transduction of HCC cell lines and subcutaneous HCC xenografts with recombinant MV-Edm resulted in high-level expression of transgenes in vitro and in vivo. MV-Edm was nontoxic in susceptible mice. Intratumoral and intravenous therapy with recombinant MV-Edm resulted in inhibition of tumor growth and prolongation of survival with complete tumor regression in up to one third of animals. In conclusion, engineered MV-Edm may be a potent and novel cancer gene therapy system for HCC. MV-Edm expressing CEA or hNIS elicited oncolytic effects in human HCC cell lines in vitro and in vivo, enabling the spread of the virus to be monitored in a noninvasive manner. (HEPATOLOGY 2006;44:1465,1477.) [source] Proteasome inhibition with bortezomib suppresses growth and induces apoptosis in osteosarcomaINTERNATIONAL JOURNAL OF CANCER, Issue 1 2010Yuriy Shapovalov Abstract Osteosarcomas are primary bone tumors of osteoblastic origin that mostly affect adolescent patients. These tumors are highly aggressive and metastatic. Previous reports indicate that gain of function of a key osteoblastic differentiation factor, Runx2, leads to growth inhibition in osteosarcoma. We have previously established that Runx2 transcriptionally regulates expression of a major proapoptotic factor, Bax. Runx2 is regulated via proteasomal degradation, and proteasome inhibition has a stimulatory effect on Runx2. In this study, we hypothesized that proteasome inhibition will induce Runx2 and Runx2-dependent Bax expression sensitizing osteosarcoma cells to apoptosis. Our data showed that a proteasome inhibitor, bortezomib, increased Runx2 and Bax in osteosarcoma cells. In vitro, bortezomib suppressed growth and induced apoptosis in osteosarcoma cells but not in nonmalignant osteoblasts. Experiments involving intratibial tumor xenografts in nude mice demonstrated significant tumor regression in bortezomib-treated animals. Immunohistochemical studies revealed that bortezomib inhibited cell proliferation and induced apoptosis in osteosarcoma xenografts. These effects correlated with increased immunoreactivity for Runx2 and Bax. In summary, our results indicate that bortezomib suppresses growth and induces apoptosis in osteosarcoma in vitro and in vivo suggesting that proteasome inhibition may be effective as an adjuvant to current treatment regimens for these tumors. Published 2009 UICC. This article is a US Government work and, as such, is in the public domain in the United States of America. [source] EGFR tyrosine kinase inhibition radiosensitizes and induces apoptosis in malignant glioma and childhood ependymoma xenograftsINTERNATIONAL JOURNAL OF CANCER, Issue 1 2008Birgit Geoerger Abstract Malignant gliomas and childhood ependymomas have a high rate of treatment failure. Epidermal growth factor receptor (EGFR) activation has been implicated in the tumorigenesis and radioresistance of many cancers, including brain tumors. Therefore, combining EGFR targeting with irradiation is a potentially attractive therapeutic option. We evaluated the tyrosine kinase inhibitor gefitinib for its antitumor activity and potential to radio-sensitize in vivo in two xenograft models: an EGFR amplified glioma and an EGFR expressing ependymoma, both derived from primary tumors. When administered at 100 mg/kg for 5 consecutive days, gefitinib-induced partial tumor regression in all treated EGFR amplified IGRG88 glioma xenografts. The addition of 1 Gy of irradiation prior to gefitinib administration resulted in 5 complete and 4 partial regressions for the 9 treated tumors as well as a significant tumor growth delay of 33 days for the combined treatment compared to 19 days for each therapy alone, suggesting additive antitumor activity. Tumor regression was associated with inhibition of AKT and MAPK pathways by gefitinib. In contrast, the ependymoma IGREP83 was sensitive to irradiation, but remained resistant to gefitinib. Combined treatment was associated with inhibition of radiation-induced MAPK phosphorylation and significant induction of apoptotic cell death though radiation-induced AKT phosphorylation was maintained. Depending on the scheduling of both therapies, a trend towards superior antitumor activity was observed with combined treatment. Thus, EGFR targeting through tyrosine kinase inhibition appears to be a promising new approach in the treatment of EGFR-driven glioma, particularly in combination with radiation therapy. © 2008 Wiley-Liss, Inc. [source] In vitro and in vivo evaluation and a case report of intense nanosecond pulsed electric field as a local therapy for human malignanciesINTERNATIONAL JOURNAL OF CANCER, Issue 3 2007Edward B. Garon Abstract When delivered to cells, very short duration, high electric field pulses (nanoelectropulses) induce primarily intracellular events. We present evidence that this emerging modality may have a role as a local cancer therapy. Five hematologic and 16 solid tumor cell lines were pulsed in vitro. Hematologic cells proved particularly sensitive to nanoelectropulses, with more than a 60% decrease in viable cells measured by MTT assay 96 hr after pulsing in 4 of 5 cell lines. In solid tumor cell lines, 10 out of 16 cell lines had more than a 10% decrease in viable cells. AsPC-1, a pancreatic cancer cell line, demonstrated the greatest in vitro sensitivity among solid tumor cell lines, with a 64% decrease in viable cells. When nanoelectropulse therapy was applied to AsPC-1 tumors in athymic nude mice, responses were seen in 4 of 6 tumors, including clinical complete responses in 3 of 6 animals. A single human subject applied nanoelectropulse therapy to his own basal cell carcinoma and had a complete pathologic response. In summary, we demonstrate that electric pulses 20 ns or less kill a wide variety of human cancer cells in vitro, induce tumor regression in vivo, and show efficacy in a single human patient. Therefore, nanoelectropulse therapy deserves further study as a potentially effective cancer therapy. © 2007 Wiley-Liss, Inc. [source] Hyaluronidase reduces human breast cancer xenografts in SCID miceINTERNATIONAL JOURNAL OF CANCER, Issue 2 2002Svetlana Shuster Abstract A hyaluronan-rich environment often correlate with tumor progression. and may be one mechanism for the invasive behavior of malignancies. Eradication of hyaluronan by hyaluronidase administration could reduce tumor aggressiveness and would provide, therefore, a new anti-cancer strategy. Hyaluronan interaction with its CD44 receptor and the resulting signal transduction events may be among the mechanisms for hyaluronan-associated cancer progression. We have shown previously that hyaluronidase treatment of breast cancer cells in vitro not only eradicates hyaluronan but also modifies expression of CD44 variant exons of tumor cells. We now determine if such effects occur in vivo and if it is accompanied by tumor regression. SCID mice bearing xenografts of human breast carcinomas were given intravenous hyaluronidase. Tumor volumes decreased 50% in 4 days. Tumor sections showed decreased hyaluronan. Intensity of staining for CD44s was not affected, whereas staining for specific CD44 variant exon isoforms was greatly reduced in residual tumors. Necrosis was not evident. Hyaluronidase, used previously as an adjunct in cancer treatment, presumably to enhance penetration of chemotherapeutic drugs, may itself have intrinsic anti-cancer activity. Removing peritumor hyaluronan appears to cause an irreversible change in tumor metabolism. Continuous hyaluronan binding to CD44 variant exon isoforms may also be required to stabilize inherently unstable isoforms that participate perhaps in tumor progression. Further investigation is required to confirm a cause and effect relationship between loss of hyaluronan, changes in CD44 variant exon expression and tumor reduction. If confirmed, hyaluronidase may provide a new class of anti-cancer therapeutics and one without toxic side effects. © 2002 Wiley-Liss, Inc. [source] Targeting the c-Myc coiled coil with interfering peptidesJOURNAL OF PEPTIDE SCIENCE, Issue 9 2008Eva M. Jouaux Abstract c-Myc is one of the most frequently deregulated oncogenes in human cancers, and recent studies showed that even brief inactivation of Myc can be sufficient to induce tumor regression or loss. Consequently, inactivation of Myc provides a novel therapeutic opportunity and challenge, as the dimerization of Myc with Max is crucial for its function. We applied two strategies to specifically target this coiled coil mediated interaction with interfering peptides: a dominant-negative human Max sequence (Max) and a peptide selected from a genetic library (Mip). Both peptides form coiled coils and were fused to an acidic extension interacting with the basic DNA-binding region of human Myc. The genetic library was obtained by semi-rational design randomizing residues important for interaction, and selection was carried out using a protein-fragment complementation assay. The peptides Max and Mip easily outcompeted the human Myc:Max interaction and successfully interfered with the DNA binding of the complex. Both interfering peptides exhibited higher Tm (,Tm = 13 and 15 °C) upon interaction with Myc compared to wt Max. The inhibitory effect of the two interfering peptides on human Myc:Max activity makes them promising molecules for analytical and therapeutic Myc-directed research. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd. [source] Regression of metastatic carcinoid tumors with octreotide therapy: Two case reports and a review of the literatureJOURNAL OF SURGICAL ONCOLOGY, Issue 3 2002Wey L. Leong MD Abstract Background The antiproliferative effect of the somatostatin analogue, octreotide, on metastatic carcinoid tumors is poorly understood. Partial tumor regression seen radiogaphically has been reported with the use of octreotide therapy for neuroendocrine tumors. Complete regression of carcinoid tumors is rarely reported. Results Two patients with metastatic midgut carcinoid tumors were treated with subcutaneous octreotide 300 ,g/day for symptomatic control of their carcinoid syndrome before debulking palliative surgery. During the laporatomies, both patients were found to have complete macroscopic regression of the metastastatic lesions that had been identified radiologically before surgery, including liver metastases in one patient and periportal and retrocaval lymph nodes in the other. After surgery, the patients were evaluated every 3 months, and had no detectable disease at 30 and 43 months, respectively. Thirty cases of partial tumor regression with octreotide administered with or without other treatment modalities have been reported in the literature. Most of the patients involved received other treatment modalities. Only one other case reported in the literature showed complete regression with octreotide monotherapy. Conclusions We report two cases of metastatic midgut carcinoid tumors that demonstrated a significant anti-proliferative response to octreotide monotherapy. Review of the literature failed to identify any specific prognostic factors with which the response to octreotide can be predicted. Possible mechanisms for this antiproliferative effect of octreotide on carcinoid tumors are discussed. J. Surg. Oncol. 2002;79:180,187. © 2002 Wiley,Liss, Inc. [source] Preliminary experience with arterial chemoembolization for hepatoblastoma and hepatocellular carcinoma in childrenPEDIATRIC BLOOD & CANCER, Issue 7 2006Piotr Czauderna MD Abstract The objective of this work was to test feasibility and efficacy of hepatic artery chemoembolization (HACE) in unresectable malignant liver tumors. Five patients aged from 1,12 years were treated in the Medical University of Gdansk from 1999 to 2002. All had locally advanced tumors, which did not respond to systemic chemotherapy: four, hepatoblastoma (HB) and one, hepatocellular carcinoma (HCC). Arteriography was performed and chemoembolization suspension (cisplatin,+,doxorubicin,+,mitomycin mixed with lipiodol) was injected, followed by gelatin foam particles. The procedure was performed one to three times in each patient. In four patients (three, HB, one, fibrolamellar HCC), tumor response was observed, with decrease in the diameter of the mass of 25,33% and fall in the AFP level of 83,99%. One child with HB was non-evaluable due to early death caused by systemic myelotoxicity. Two patients (2 HB) underwent macroscopically complete tumor resection, 1 is alive and well, and 1 died at the end of surgery for an unknown reason (possibly related to cardiotoxicity of earlier systemic chemotherapy). One HB patient was successfully transplanted after two HACE courses. The only HCC patient died because of pulmonary oil embolism immediately after the third HACE course. HACE can lead to tumor regression in most cases and may be considered an alternative for patients with unresectable liver tumors who do not respond to primary systemic chemotherapy and are not candidates for liver transplantation for various reasons. © 2005 Wiley-Liss, Inc. [source] The Relationship of Phthalocyanine 4 (Pc 4) Concentrations Measured Noninvasively to Outcome of Pc 4 Photodynamic Therapy in MicePHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2009Lihua Bai The ability to noninvasively measure photosensitizer concentration at target tissues will allow optimization of photodynamic therapy (PDT) and could improve outcome. In this study, we evaluated whether preirradiation tumor phthalocyanine 4 (Pc 4) concentrations, measured noninvasively by the optical pharmacokinetic system (OPS), correlated with tumor response to PDT. Mice bearing human breast cancer xenografts were treated with 2 mg kg,1 Pc 4 iv only, laser irradiation (150 J cm,2) only, Pc 4 followed by fractionated irradiation or Pc 4 followed by continuous irradiation. Laser irradiation treatment was initiated when the tumor to skin ratio of Pc 4 concentration reached a maximum of 2.1 at 48 h after administration. Pc 4 concentrations in tumor, as well as in Intralipid in vitro, decreased monoexponentially with laser fluence. Pc 4-PDT resulted in significant tumor regression, and tumor response was similar in the groups receiving either fractionated or continuous irradiation treatment after Pc 4. Tumor growth delay following Pc 4-PDT correlated with OPS-measured tumor Pc 4 concentrations at 24 h prior to PDT (R2 = 0.86). In excised tumors, OPS-measured Pc 4 concentrations were similar to the HPLC-measured concentrations. Thus, OPS measurements of photosensitizer concentrations can be used to assist in the scheduling of Pc 4-PDT. [source] 1,25D3 Enhances antitumor activity of gemcitabine and cisplatin in human bladder cancer models,CANCER, Issue 13 2010Yingyu Ma MD Abstract BACKGROUND: 1,25 dihydroxyvitamin D3 (1,25D3) potentiates the cytotoxic effects of several common chemotherapeutic agents. The combination of gemcitabine and cisplatin is a current standard chemotherapy regimen for bladder cancer. The authors investigated whether 1,25D3 could enhance the antitumor activity of gemcitabine and cisplatin in bladder cancer model systems. METHODS: Human bladder cancer T24 and UMUC3 cells were pretreated with 1,25D3 followed by gemcitabine and cisplatin. Apoptosis was assessed by annexin V staining. Caspase activation was examined by immunoblot analysis and substrate-based caspase activity assay. The cytotoxic effects were examined by using 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and in vitro clonogenic assay. p73 protein levels were assessed by immunoblot analysis. Knockdown of p73 was achieved by siRNA. The in vivo antitumor activity was assessed by in vivo excision clonogenic assay and tumor regrowth delay in the T24 xenograft model. RESULTS: 1,25D3 pretreatment enhanced gemcitabine and cisplatin-induced apoptosis and the activities of caspases 8, 9, and 3 in T24 and UMUC3 cells. 1,25D3 synergistically reduced gemcitabine and cisplatin-suppressed surviving fraction in T24 cells. 1,25D3, gemcitabine, or cisplatin induced p73 accumulation, which was enhanced by gemcitabine and cisplatin or 1,25D3 and gemcitabine and cisplatin. p73 expression was lower in human primary bladder tumor tissue compared with adjacent normal tissue. Knockdown of p73 increased clonogenic capacity of T24 cells treated with 1,25D3, gemcitabine and cisplatin, or 1,25D3 and gemcitabine and cisplatin. 1,25D3 and gemcitabine and cisplatin combination enhanced tumor regression compared with 1,25D3 or gemcitabine and cisplatin alone. CONCLUSIONS: 1,25D3 potentiates gemcitabine and cisplatin-mediated growth inhibition in human bladder cancer models in vitro and in vivo, which involves p73 induction and apoptosis. Cancer 2010; 116:3294-303. © 2010 American Cancer Society. [source] The predictive value of apoptosis protease-activating factor 1 in rectal tumors treated with preoperative, high-dose-rate brachytherapyCANCER, Issue 2 2006Inti Zlobec M.Sc. Abstract BACKGROUND The objective of this study was to assess the value of apoptosis protease-activating factor 1 (APAF-1) as a predictive marker of response in rectal tumors treated with preoperative, high-dose-rate endorectal brachytherapy. METHODS Immunohistochemistry for APAF-1 was performed on 94 rectal tumor biopsy specimens from patients who were treated on a preoperative, high-dose-rate brachytherapy protocol. Tumors were considered positive when > 10% of tumor cells were immunoreactive. The association between APAF-1 expression and tumor response was made using the chi-square test. RESULTS Forty-four tumors (43%) were positive for APAF-1. Thirty tumors had complete pathologic tumor regression after preoperative radiotherapy. Of these, 18 tumors were positive for APAF-1. A partial response occurred in 35 tumors. Eighteen tumors (51%) were positive for the protein. Only 8 of 29 nonresponsive tumors (28%) were immunoreactive for APAF-1. A significant association was found between complete tumor regression and positive APAF-1 status (P = 0.018). APAF-1 expression in partially responsive tumors was significantly greater than in nonresponsive tumors (P = 0.03). CONCLUSIONS APAF-1 expression in pretreatment rectal tumor biopsy specimens may be useful as a predictive marker of response to preoperative radiotherapy in patients with rectal carcinoma. Cancer 2006. © 2005 American Cancer Society. [source] A phase II trial of arsenic trioxide in patients with metastatic melanomaCANCER, Issue 8 2005Kevin B. Kim M.D. Abstract BACKGROUND Arsenic trioxide induces growth inhibition and apoptosis in human melanoma cell lines. Therefore, a Phase II trial was conducted to evaluate the efficacy and toxicity of single-agent arsenic trioxide in patients with Stage IV melanoma. METHODS Twenty patients, 10 with metastatic melanoma of cutaneous origin and 10 with metastatic melanoma of choroidal origin, received arsenic trioxide 0.25 mg/kg/day for 5 days, followed by a maintenance dose of 0.35 mg/kg/day twice a week. All patients with melanoma of cutaneous origin and four patients with melanoma of choroidal origin had received prior therapy. RESULTS Single-agent arsenic trioxide did not induce clinical response in this patient population. Eight patients (five with melanoma of cutaneous origin, and three with melanoma of choroidal origin) had disease stabilization for at least six weeks. The median overall survival duration for patients with melanoma of cutaneous origin was 7.9 months, and that of patients with melanoma of choroidal origin has not been reached at a median follow-up duration of 11.8 months. Grade 3 toxicity included neutropenia, fatigue, abdominal pain, and arthralgia. Grade 4 toxicity did not occur. CONCLUSIONS Single-agent arsenic trioxide was generally well tolerated; however, no tumor regression was observed in this patient population. Future clinical trials should evaluate arsenic trioxide in combination with other anticancer drugs that may improve its clinical activity in melanoma. Cancer 2005. © 2005 American Cancer Society. [source] Receptor activator of NF-,B ligand, macrophage inflammatory protein-1,, and the proteasomeCANCER, Issue S3 2003Novel therapeutic targets in myeloma Abstract BACKGROUND The bone destruction in myeloma patients is largely responsible for the clinical features of the disease. However, only recently has attention focused on identifying and developing drugs targeted specifically at the osteolysis. Receptor activator of NF-,B ligand (RANKL), macrophage inflammatory protein (MIP)-1,, and proteasomal function have been implicated in the pathogenesis of myeloma and associated bone disease. We provide "proof of principle" in preclinical myeloma models that these are indeed valid molecular targets in development of novel therapeutics. METHODS The efficacy of antagonists of RANKL and MIP-1, bioactivities (RANK.Fc and neutralizing monoclonal anti-MIP-1, antibody) in ameliorating osteolysis and reducing tumor burden was evaluated in a mouse model in which murine myeloma 5TGM1 cells are injected intravenously into syngeneic mice. In addition, the activity of a petidyl aldehyde proteasome inhibitor (proteasome inhibitor-1 [PSI]) on tumor growth was tested in a murine 5TGM1 plasmacytoma model and in mice intravenously inoculated with 5TGM1 cells. RESULTS RANK.Fc and anti-MIP-1, antibody inhibited the development and progression of osteolytic lesions and significantly reduced tumor load assessed by serum monoclonal paraprotein titers. Intratumoral injections of PSI inhibited growth of 5TGM1 plasmacytomas and induced tumor regression in some cases. In addition, systemic administration of PSI significantly prolonged time to onset of paraplegia in tumor-bearing mice. CONCLUSIONS The results highlight the critical roles of RANKL and MIP-1, in the development and progression of myeloma and provide a basis for future evaluation in myeloma patients of novel therapeutics that disrupt interactions of RANKL and MIP-1, with their cognate receptors. The data also suggest that further studies in preclincal myeloma models aimed at identifying other proteasome inhibitors with antitumor efficacy would be worthwhile. Cancer 2003;97(3 Suppl):813,7. © 2003 American Cancer Society. DOI 10.1002/cncr.11133 [source] Inhibition of heat shock protein 90 sensitizes melanoma cells to thermosensitive ferromagnetic particle-mediated hyperthermia with low Curie temperatureCANCER SCIENCE, Issue 3 2009Aki Ito Heat shock protein (Hsp) 90 is a key regulator of a variety of oncogene products and cell-signaling molecules, and the therapeutic benefit of its inhibition in combination with radiation or chemotherapy has been investigated. In addition, hyperthermia has been used for many years to treat various malignant tumors. We previously described a system in which hyperthermia was induced using thermosensitive ferromagnetic particles (FMP) with a Curie temperature (Tc = 43,C) low enough to mediate automatic temperature control, and demonstrated its antitumor effect in a mouse melanoma model. In the present study, we examined the antitumor effects of combining a Hsp90 inhibitor (geldanamycin; GA) with FMP-mediated hyperthermia. In cultured B16 melanoma cells, GA exerted an antitumor effect by increasing the cells' susceptibility to hyperthermia and reducing expression of Akt. In an in vivo study, melanoma cells were subcutaneously injected into the backs of C57BL/6 mice. FMP were then injected into the resultant tumors, and the mice were divided into four groups: group I, no treatment (control); group II, one hyperthermia treatment; group III, GA alone; and group IV, GA with hyperthermia. When exposed to a magnetic field, the temperature of tissues containing FMP increased and stabilized at the Tc. In group IV, complete regression of tumors was observed in five of nine mice (56%), whereas no tumor regression was seen in groups I,III. Our findings suggest that inhibition of Hsp90 with hyperthermia increases its antitumor effect. Thus, the combination of FMP-mediated, self-regulating hyperthermia with Hsp90 inhibition has important implications for the treatment of cancer. (Cancer Sci 2009; 100: 558,564) [source] Local interferon-, gene therapy elicits systemic immunity in a syngeneic pancreatic cancer model in hamsterCANCER SCIENCE, Issue 3 2007Hidehiko Hara The interferon (IFN) protein is a cytokine with pleiotropic biological functions that include induction of apoptosis, inhibition of angiogenesis and immunomodulation. We previously examined the two antitumor mechanisms, taking advantage of the fact that IFN-, did not show cross-species activity in its in vivo effect. In a nude mouse subcutaneous xenograft model using human pancreatic cancer cells, the expression of human IFN-, effectively induced cell death of human pancreatic cancer cells, whereas mouse IFN-, augmented antitumor immunity by stimulation of natural killer cells. Here, we extended our investigation to a syngeneic pancreatic cancer model, so that the integrated antitumor activity of local IFN-, gene therapy, including the antiproliferative, proapoptotic, antiangiogeneic and immunomodulatory effects, can be evaluated rigorously. When a recombinant hamster IFN-, adenovirus was injected into syngeneic subcutaneous tumors of hamster pancreatic cancer (PGHAM-1) cells in Syrian hamster, tumor growth was significantly suppressed due to cell death and T cell- and natural killer cell-mediated antitumor immunity. Moreover, in this case, tumor regression was observed not only for the injected subcutaneous tumors but also for the untreated tumors both in the peritoneal cavity and at distant sites. No significant systemic toxicity was observed in the treated hamsters. Moreover, the subcutaneous rechallenge of PGHAM-1 cells was rejected in three of four cured hamsters from the initial tumor challenge. This study further demonstrated that local IFN-, gene therapy is a promising therapeutic strategy for pancreatic cancer, due to its multiple mechanisms of antitumor activity and its lack of significant toxicity. (Cancer Sci 2007; 98: 455,463)) [source] Anticancer effects of ZD6474, a VEGF receptor tyrosine kinase inhibitor, in gefitinib ("Iressa")-sensitive and resistant xenograft modelsCANCER SCIENCE, Issue 12 2004Fumiko Taguchi ZD6474 is a novel, orally available inhibitor of vascular endothelial growth factor (VEGF) receptor-2 (KDR) tyrosine kinase, with additional activity against epidermal growth factor receptor (EGFR) tyrosine kinase. ZD6474 has been shown to inhibit angiogenesis and tumor growth in a range of tumor models. Gefitinib ("Iressa") is an selective EGFR tyrosine kinase inhibitor (TKI) that blocks signal transduction pathways. We examined the antitumor activity of ZD6474 in the gefitinib-sensitive lung adenocarcinoma cell line, PC-9, and a gefitinib-resistant variant (PC-9/ZD). PC-9/ZD cells showed cross-resistance to ZD6474 in an in vitro dye formation assay. In addition, ZD6474 showed dose-dependent inhibition of EGFR phosphorylation in PC-9 cells, but inhibition was only partial in PC-9/ZD cells. ZD6474-mediated inhibition of tyrosine residue phosphorylation (Tyr992 and Tyr1045) on EGFR was greater in PC-9 cells than in PC-9/ZD cells. These findings suggest that the inhibition of EGFR phosphorylation by ZD6474 can contribute a significant, direct growth-inhibitory effect in tumor cell lines dependent on EGFR signaling for growth and/or survival. The effect of ZD6474 (12.5,50 mg/kg/day p.o. for 21 days) on the growth of PC-9 and PC-9/ZD tumor xenografts in athymic mice was also investigated. The greatest effect was seen in gefitinib-sensitive PC-9 tumors, where ZD6474 treatment (>12.5 mg/kg/day) resulted in tumor regression. Dose-dependent growth inhibition, but not tumor regression, was seen in ZD6474-treated PC-9/ZD tumors. These studies demonstrate that the additional EGFR TKI activity may contribute significantly to the anti-tumor efficacy of ZD6474, in particular in those tumors that are dependent on continued EGFR-signaling for proliferation or survival. In addition, these results provide a preclinical rationale for further investigation of ZD6474 as a potential treatment option for both EGFR-TKI-sensitive and EGFR-TKI-resistant tumors. [source] Herpes simplex virus-induced, death receptor-dependent apoptosis and regression of transplanted human cancersCANCER SCIENCE, Issue 12 2004Hironaga Kamiyama Inoculation of a live attenuated herpes simplex virus (HSV) vector, bH1, into human U87MG glioblastoma cells transplanted into athymic nude mice induced complete regression of tumors. The infected cells underwent histochemically confirmed apoptosis without lymphocyte infiltration after expressing CD30, CD30 ligand (CD30L), tumor necrosis factor (TNF)-a, TNF receptor 1 (TNF-R1), FAS, and FAS ligand (FAS-L) with activation of caspases 3 and 8. Induction of the transcripts of these receptors and ligands in inoculated tumors was confirmed by quantitative RT-PCR. To examine the specificity of apoptosis in the transplanted tumor, we inoculated bH1 into transplanted human lung, breast, gastric, and colon cancer tumors, and similar tumor regression with apoptosis was observed in all tumors. We analyzed the roles of expression of CD30, CD30L, TNF-a, TNF-R1, FAS, and FAS-L in the tumors, and found that HSV-induced apoptosis was suppressed by the respective antibodies. These findings indicate that the CD30/CD30L, TNF-a/TNF-R1, and FAS/FAS-L interactions resulted in apoptosis and tumor regression in immunocompromised mice. In addition to the death receptor-dependent apoptosis induced by HSV, the expressed ligands and receptors might enhance the susceptibility of tumor cells to cell-mediated cyto-toxicity and augment the activation of tumor-killing lymphocytes in immunocompetent models. [source] | |||||||||||||