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Organ- and tissue-specific stem cells and carcinogenesis.

Tissue-specific cancers originate in organ- or tissue-specific cells with the potential to proliferate. Recent reports have shown that every adult tissue may have its own stem cells. Cancer cells and organ- and tissue-specific stem cells and other progenitor cells are strikingly similar: both types self-renew, proliferate indefinitely, migrate, differentiate and express telomerase. Telomerase is a ribonucleoprotein that adds on nucleotides to the telomeres of chromosomes and so protects them from degradation, recombination and fusion at double-stranded DNA breaks. Cancer cells differ from normal tissue-specific stem cells only in their uncontrolled growth and altered genotypes. Based on the many similarities between cancer cells and stem cells, I propose that cancers (both solid and hematopoietic) arise from tissue-specific stem cells. Some such stem cells are always present among the stem cells in the peripheral blood of cancer patients and some of their asymptomatic first-degree relatives. It may therefore be possible to diagnose cancer predisposition early by identifying these circulating stem cells by their genetic defects. I, therefore, suggest that drug development for cancer treatment be directed towards tissue-specific stem cells.

Animals↗

High-dose chemotherapy with peripheral blood stem cell transplantation for patients with advanced ovarian cancer.

PURPOSE: We report the results of high-dose chemotherapy (HDC) with peripheral blood stem cell transplantation in twenty-one patients with primarily advanced or relapsed ovarian cancer. METHODS: Twenty-five women underwent stem cell collection, and 21 were finally treated with different regimens of HDC containing cyclophosphamide, etoposide, carboplatin, and treosulfan. The patients received cyclophosphamide +/- cisplatin and cisplatin + paclitaxel, respectively, followed by G-CSF (n = 24) or GM-CSF (n = 1) for stem cell mobilization. RESULTS: A mean of 7.2 +/- 6.1 x 10(6) CD34+ cells per kg bw were collected. Thirteen patients received double transplants and one patient received a triple transplant. The median age was 47 years (range 24-61 years) and the mean number of prior regimens was three (range 1-8). Engraftment occurred on time in all patients and there was one treatment-related death resulting in an overall mortality rate of 4.8% among the 21 patients treated with HDC. The response rate was 72% (48% CR, 24% PR) and the mean time to progression and overall survival after HDC were 7 and 32 months, respectively. CONCLUSION: HDC could be performed safely in patients with advanced ovarian cancer. However, even with a high response rate, the duration of response is short, warranting new treatment approaches to further improve the outcome of this population of patients with unfavorable prognosis.

Adult↗

Early cystic/necrotic changes after hyperfractionated radiation therapy in children with brain stem gliomas. Data from the Childrens Cancer Group.

BACKGROUND: A higher total dose of radiation therapy administered in fractionated lower individual doses twice daily (hyperfractionated radiation therapy) has been reported to improve survival for children with brain stem gliomas. However, this higher dose of radiation therapy may cause more sequelae. METHOD: Eighty-eight children with brain stem gliomas were treated with 100 cGy twice daily to a total dose of 7200 cGy. Patients were carefully followed up for treatment-related clinical or radiographic worsening. RESULTS: Thirteen (15%) had intralesional cystic/necrotic changes within 8 weeks of completion of treatment. Children with these changes had a variable clinical course, including steady deterioration in one child; initial improvement, followed by progressive deterioration in three; and initial improvement, followed by deterioration, with subsequent improvement or prolonged stabilization of condition without additional antineoplastic treatment in nine. CONCLUSION: This latter "triphasic" course suggests that "early" worsening after hyperfractionated radiation therapy at 7200 cGy may be a sequelae of therapy, rather than a symptom of progressive tumor growth. This has substantial implications for patient care and evaluation of the efficacy of treatment.

Adult↗

Transduction potential of human retroviruses in highly proliferating small-cell lung cancer cells as well as non-proliferating hematopoietic stem cells.

Direct gene transfer to solid tissues or metastatic cancer cells requires vectors capable of in vivo transduction to specific cells. The predominant retroviral vectors of murine origin are inactivated by human complement, which precludes their use in vivo. Such inactivation does not take place with vectors based on human retroviruses. Murine retroviral vectors are also limited to proliferating cells, which human retroviruses are not. In this study we examined whether or not a vector using components from the human retroviruses HIV-1 and HTLV-1 could infect small-cell lung cancer cells and resting CD34+ hematopoietic stem cells. While HIV-1 itself was unable to infect cells lacking the CD4-membrane molecule, chimeric viral particles (pseudotype virus) with HIV-1 genome and HTLV-1 envelope components were able to infect both CD4-containing lymphocytic cells, CD4-negative tumour cells and hematopoietic stem cells. After infection with the pseudotype vector, the RNA genome was reverse transcribed and integrated. Transduction efficiency and gene expression under the HIV-1 LTR promoter in both tumour and stem cells were found to be of a similar or greater magnitude than in lymphocytic cells. These results suggest that gene transfer targeting proliferating as well as resting cells in vivo may be realized using components from human retroviruses.

Antigens, CD34↗

Stem cells in normal breast development and breast cancer.

The main focus of this review is the role of mammary stem cells in normal breast development and carcinogenesis. We have developed a new in vitro culture system that permits, for the first time, the propagation of mammary stem and progenitor cells in an undifferentiated state, which should facilitate the elucidation of pathways that regulate normal mammary stem-cell self-renewal and differentiation. Furthermore, we propose a model in which transformation of stem cells, or early progenitor cells, results in carcinogenesis. A key event in this process is the deregulation of normal self-renewal in these cells. Transformed mammary stem or progenitor cells undergo aberrant differentiation processes that result in generation of the phenotypic heterogeneity found in human and rodent breast cancers. This phenotypic diversity is driven by a small subset of mammary tumour stem cells. We will discuss the important implications of this mammary tumour stem-cell model.

Animals↗

[Chemohyperthermic peritoneal perfusion and high-dose chemotherapy followed by peripheral blood stem cell transplantation in advanced colon cancer--a case report].

A 49-year-old woman who suffered from caecal cancer in 1988 underwent chemohyperthermic peritoneal perfusion for peritoneal and ovarian metastases in 1990, and high dose chemotherapy (HDC) with peripheral blood stem cell transplantation (PBSCT) for lung metastases in 1995. Heated saline containing anticancer drugs such as cisplatin, mitomycin C, etoposide (ETP), and pirarubicin, was intraperitoneally perfused at 43 degrees C for 60 minutes. The CD34 positive cells were mobilized by intravenous 500 micrograms G-CSF administration on five consecutive days. These cells were transplanted three days after the last day in the course of HDC, which included intravenous administration of 475 mg carboplatin, 2,020 mg cyclophosphamide, and 540 mg etoposide. The patient has survived with no sign of the disease.

Antineoplastic Combined Chemotherapy Protocols↗

High-dose chemotherapy with peripheral blood stem cell transplantation for advanced testicular cancer.

BACKGROUND: The aim of this study was to investigate the efficacy and safety of high-dose chemotherapy (HDCT) for the treatment of patients with advanced testicular cancer. METHODS: Fourteen patients were treated with high-dose carboplatin, etoposide and cyclophosphamide (with or without THP-adriamycin) followed by peripheral blood stem cell transplantation. The treatment was used for two refractory cases, a second relapse, and for consolidation after the first relapse in one case each. It was also used for nine cases as part of the first-line treatment following primary conventional-dose chemotherapy, and for one case as the first salvage for a late recurrent tumor of teratoma with malignant transformation. RESULTS: The first two patients who received intensive pretreatment with cisplatin-based chemotherapy did not respond to HDCT. The two patients who were treated with HDCT as the first or second salvage therapy achieved successful outcomes. The results for the subsequent nine patients (consisting of two with stage IIIC, five with IIIB2, one with IIB, and one extragonadal seminoma) were two progressive disease, three no change and four partial remission. Only three are alive with NED following salvage surgery. Finally, a case of teratoma with malignant transformation did not respond well to two cycles of HDCT. There were no marked adverse reactions except one episode of severe neutropenic colitis. CONCLUSIONS: The results demonstrated the limited efficacy of HDCT even in cases with a good to intermediate risk rating according to classification by the International Germ Cell Cancer Collaborative Group. Because treatment for relapse after HDCT is extremely difficult, new HDCT regimens consisting of drugs that are not used in induction chemotherapy need to be established.

Adolescent↗

Effect of different chemotherapy regimens on peripheral-blood stem-cell collections in patients with breast cancer receiving granulocyte colony-stimulating factor.

PURPOSE: To evaluate the effects of chemotherapy regimens on peripheral-blood stem-cell (PBSC) yields in patients with breast cancer who receive granulocyte colony-stimulating factor (G-CSF). PATIENTS AND METHODS: One hundred patients with breast cancer received cyclophosphamide 4 g/m2 for dose (CY) (n = 10), CY and etoposide 600 mg/m2 (CE) (n = 13), CE and cisplatin 105 mg/m2 (CEP) (n = 19), or CY and paclitaxel 170 mg/m2 (n = 58), followed by G-CSF. PBSC collections were initiated when the WBC count recovered to greater than 1 x 10(9)/L. A multivariate analysis was undertaken to evaluate the effects of different chemotherapy regimens and patient variables on PBSC collections as measured by the yield of CD34+ cells. RESULTS: The medians of average daily CD34+ cell yields for patients who received paclitaxel plus CY, CE, and CEP with G-CSF were 12.9, 11.03, and 5.37 x 10(6)/kg, respectively, compared with 2.02 x 10(6)/kg in the reference group that received CY with G-CSF (P = < .0001, .002, and .09, respectively). On first-day collections, patients who received paclitaxel plus CY, CE, and CEP with G-CSF yielded medians of 11.07, 8.09, and 3.52 x 10(6) CD34+ cells/kg, respectively, compared with 0.90 x 10(6)/kg in the reference group that received CY with G-CSF (P = .0006, .02, and .09, respectively). The number of previous cycles of chemotherapy, previous radiotherapy, marrow involvement, and phase and stage of disease did not have statistically significant effects on CD34+ cell yield. CONCLUSION: Combination chemotherapy regimens were superior to single-agent CY for the mobilization of CD34+ cells.

Antigens, CD34↗

Phase II trial of high-dose chemotherapy with autologous stem cell transplant for stage IV breast cancer with minimal metastatic disease.

The purpose of this study was to assess the efficacy of high-dose chemotherapy (HDC) with autologous stem cell transplant in stage IV breast cancer patients with minimal metastases. Eligible patients had (a) disease that could be resected en bloc and/or irradiated with curative intent using a single field and could, thus, be rendered as having no evidence of disease (NED); and/or (b) <5% bone marrow involvement. From September 1991 to August 1997, 40 consecutive patients were prospectively entered on the study. Pre-HDC local treatment consisted of surgery (n = 31) and radiotherapy (XRT; n = 3). All patients received HDC with cyclophosphamide, cisplatin, and 1,3-bis(2-chloroethyl)-1-nitrosourea and autologous stem cell transplant, with or without CD34 selection. Following HDC, 22 patients received XRT. Four patients died of treatment-related complications. Eighteen patients developed grade 3 nonhematological toxicities (15 lung, 2 cardiomyopathy, and 1 optic neuritis), which resolved with therapy. Within a median follow-up of 49 (15-91) months, 14 patients had relapsed. Twenty-five patients (62.5%) were alive, and 22 patients (55%) were alive and free of disease. Median event-free and overall survivals were 43 and 77 months, respectively. In the subset of patients with one metastatic site, 17 of 24 (68%) remained relapse free. Grade 2 tumors, a single metastatic site, and delivery of XRT were favorable predictors of relapse-free survival in univariate but not multivariate analyses. Inclusion of HDC, as described, in the multimodal treatment of stage IV breast cancer patients with minimal metastases is promising. These results warrant prospective randomized trials with a HDC-containing arm in this patient population.

Adult↗

Immune reconstitution following high-dose chemotherapy with stem cell rescue in patients with advanced breast cancer.

The present study examines the nature of humoral and cellular immune reconstitution in 28 patients with advanced breast cancer following high-dose chemotherapy with stem cell rescue. Patients underwent testing of T, B, NK and dendritic cell function at serial time points until 1 year post transplant or until the time of disease progression. Abnormalities in T cell phenotype and function were observed following high-dose chemotherapy that persisted for at least 6-12 months. The vast majority of patients experienced an inversion of the CD4/CD8 ratio and demonstrated an anergic response to candida antigen. Mean T cell proliferation in response to PHA and to co-culture with allogeneic monocytes was significantly compromised. In contrast, mean IgG and IgA levels were normal 6 months post transplant and NK cell yields and function were transiently elevated following high-dose chemotherapy. Dendritic cells generated from peripheral blood progenitors displayed a characteristic phenotype and were potent inducers of allogeneic T cell proliferation in the post-transplant period. The study demonstrates that patients undergoing autologous transplantation for breast cancer experience a prolonged period of T cell dysfunction. In contrast, B, NK, and DC recover more rapidly. These findings carry significant implications for the design of post-transplant immunotherapy.

Adult↗

High-dose sequential chemotherapy with recombinant granulocyte colony-stimulating factor and repeated stem-cell support for inflammatory breast cancer patients: does impact on quality of life jeopardize feasibility and acceptability of treatment?

PURPOSE: This study was designed to investigate the quality of life (QOL) of patients enrolled onto the High-Dose Chemotherapy for Breast Cancer Study Group trial (PEGASE 02), a French pilot multicenter trial of the treatment of inflammatory breast cancer (IBC) aimed at evaluating (1) toxicity and feasibility of sequential high-dose chemotherapy (HDC) with recombinant human granulocyte colony-stimulating factor (filgrastim) and stem-cell support and (2) response to HDC in terms of pathologic response and survival. PATIENTS AND METHODS: QOL measures were performed at inclusion and four times subsequently up to 1 year using an ad hoc side-effect questionnaire (19 physical symptoms) and the European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire (EORTC QLQ-C30). RESULTS: Of the 95 patients entered, the overall QOL questionnaire completion compliance was 75.6%. During cycle 3 of HDC, the number of symptoms was high (mean +/- SD QOL score, 10 +/- 3), with fatigue, hair loss, appetite loss, nausea, change in taste, vomiting, fever, and weight loss reported by more than 60% of patients. Toxicity and distress associated with HDC were reflected in the decline of four EORTC QLQ-C30 scores: global QOL (P =.001), and physical, role, and social functioning (P <.001 for all statistics). However, QOL deterioration disappeared after treatment completion, except for physical functioning (P =.025). One year after inclusion, most QOL scores returned to baseline, and both emotional functioning and global QOL scores were even higher than baseline (P =.030 and P =.009, respectively). CONCLUSION: If it is confirmed that improvements in pathologic response rates with HDC effectively translate into increased probabilities of survival for IBC patients, adoption of such treatment as PEGASE 02 will not involve crucial choices between length of life and QOL and should not be delayed for QOL arguments.

Activities of Daily Living↗

Allogeneic hematopoietic stem cell transplantation for metastatic breast cancer.

The prognosis is poor and the options are limited for patients with metastatic breast cancer (MBC), especially for those patients who have previously received taxanes and anthracyclines; treatment strategies are primarily palliative. Murine models have demonstrated that allogeneic T cells are capable of eliciting graft-versus-tumor (GVT) effects against breast cancer, inhibiting growth of breast cancer cell lines in vivo, providing the rationale to pursue allogeneic adoptive cellular therapy as a strategy to treat MBC. However, the clinical application of allogeneic hematopoietic stem cell transplantation (alloHSCT) was limited by concerns over toxicity and unproven efficacy. The development of non-myeloablative (a.k.a. reduced-intensity) conditioning regimens, which have less treatment-related mortality but preserve the T-cell mediated GVT effects, led to increased investigation of alloHSCT in MBC. Early reports of non-myeloablative alloHSCT indicate that a clinical GVT effect against breast cancer does exist. The responses, observed in 20-40% of patients, appear to be associated with the development of complete donor lymphoid chimerism and may be delayed. In its current form, alloHSCT by itself is unlikely to result in complete eradication of MBC; however, it may serve as a therapeutic platform to complement and enhance the effects of existing cytotoxic therapies and immunotherapies (e.g. trastuzumab), as well as therapies under development (e.g. vaccines). Current data on alloHSCT for MBC should be interpreted cautiously and carefully used for the design of future studies to fully determine the clinical efficacy of this form of adoptive cellular therapy in MBC.

Animals↗

Loss of the human polycomb group protein BMI1 promotes cancer-specific cell death.

The polycomb group protein BMI1 has been shown to support normal stem cell proliferation via its putative stem cell factor function, but it is not known if BMI1 may also act as a cancer stem cell factor to promote cancer development. To determine the role of human BMI1 in cancer growth and survival, we performed a loss-of-function analysis of BMI1 by RNA interference (RNAi) in both normal and malignant human cells. Our results indicate that BMI1 is crucial for the short-term survival of cancer cells but not of normal cells. We also demonstrated that loss of BMI1 was more effective in suppressing cancer cell growth than retinoid-treatment, and surviving cancer cells showed significantly reduced tumorigenicity. The cancer-specific growth retardation was mediated by an increased level of apoptosis and a delayed cell cycle progression due to the loss of BMI1. By comparison, BMI1 deficiency caused only a moderate inhibition of the cell cycle progression in normal lung cells. In both normal and cancer cells, the loss of BMI1 led to an upregulation of INK4A-ARF, but with no significant effect on the level of telomerase gene expression, suggesting that other BMI1-cooperative factors in addition to INK4A-ARF activation may be involved in the BMI1-dependent cancer-specific growth retardation. Thus, human BMI1 is critical for the short-term survival of cancer cells, and inhibition of BMI1 has minimal effect on the survival of normal cells. These findings provide a foundation for developing a cancer-specific therapy targeting BMI1.

Apoptosis↗

Antiproliferative activity of human interferons against ovarian cancer cells grown in human tumor stem cell assay.

Fresh biopsies from 14 of 22 (64%) ovarian carcinomas cultivated in the human tumor stem cell assay (HTSCA) were sensitive (greater than 70% inhibition in cell growth) to human interferons (HuIFNs). To achieve 70% inhibition of colony growth, 500 units/ml of a naturally produced IFN-alpha or IFN-alpha A were required in 71% of the sensitive specimens. The antiproliferative potencies of five IFNs were evaluated including two native alpha IFNs, two highly purified cloned subtypes of IFN-alpha, IFN-alpha D and IFN-alpha A, and one native fibroblast-derived beta interferon (IFN-beta). The antiviral activity of the IFN-alpha as determined by a human cell target correlated with their relative antiproliferative action. IFN-alpha D had minimal inhibitory effect at the highest concentration tested, while three IFN-alpha with high antiviral activities were equivalent with respect to growth inhibition in the HTSCA. Although instability could not be eliminated as a contributing factor, IFN-beta had significantly less growth inhibitory potency for cells from ovarian cancers when compared simultaneously with native IFN-alpha in the human tumor stem cell assay (HTSCA). Assuming direct antiproliferative effects are primary, future clinical trials evaluating IFN-alpha in ovarian cancer may require high titers of IFN.

Cell Division↗

Ototoxicity after high-dose chemotherapy with cyclophosphamide, thiotepa and carboplatin followed by stem cell transplantation in patients with breast cancer.

Our purpose was to determine the risk of ototoxicity in breast cancer patients receiving a myeloablative regimen consisting of cyclophosphamide 6000 mg/m2, thiotepa 500 mg/m2 and carboplatin 800 mg/m2 (CTCb) followed by stem cell transplantation. Fourteen consecutive patients with breast cancer were treated with high dose chemotherapy consisting of the CTCb regimen followed by stem cell transplantation. A pretransplant complete hearing study was obtained which consisted of hearing case history, audiometry and tympanometry. In addition, DPOAE (Distortion Product Otoaccoustic Emissions) was done to evaluate measurable changes in the cochlear (outer hair cell) functioning. Pre-transplant, all patients had no clinical evidence of hearing impairment and hearing studies were normal. Eleven patients had hearing studies and a telephone interview posttransplant. One patient was lost to follow-up and two patients died. One of the 11 patients tested had an abnormal post-transplant hearing study but none of them had clinically detectable hearing impairment. In our prospective study of breast cancer patients treated with the CTCb regimen, we did not observe clinically detectable hearing impairment in any of the patients tested.

Adult↗