Biomedical subjects

S Filip

Publications and source records attributed to S Filip.

At least 19 recordsLinked to original sources

PubMed2006

Stem cell plasticity and carcinogenesis.

Presently, there is more and more talk about tumors being a disease connected with stem cells. Both stem cells and tumor cells have many similarities, and there is much evidence that microenvironment, cytokines and signal pathways control tissue specificities and have a significant role in the process of carcinogenesis. Recent experimental results show that stem cells and tumor stem cells apparently play a key role in carcinogenesis. Tumors grow up, thanks to the activity of just few stem cells that continuously produce other proliferating progenitor tumor cells. Generally, tumor elements are thought to be either undifferentiated, or dedifferentiated cells. Actually, the truth is that tumors are made of more or less differentiated cells with variable rate of differentiation. We suppose that under certain conditions tumor stem cells may participate in regeneration without giving rise to tumor formation. It is also presumed that we may reprogram tumor stem cells and progenitor cells in a certain period of time and so initiate development of normal tissue. However, till now the real relation between normal and tumor cells is not clear. Finally, we wish to remind that plasticity of tumor and normal cells cannot be separated but should be considered as individual phenomenon expressing certain condition of an organism in time. This communication is only a probe and introduction into a discussion aimed at better understanding of carcinogenesis from the view of processes at the stem cell level. Stimulation of stem cell activation may lead to prophylactic approaches for therapy and prevention in carcinogenesis.

Animals↗

PubMed2005

The transplantation of neural stem cells and predictive factors in hematopoietic recovery in irradiated mice.

A number of surprising observations have shown that stem cells, in suitable conditions, have the ability to produce a whole spectrum of cell types, regardless, whether these tissues are derived from the same germ layer or not. This phenomenon is called stem cell plasticity, which means that tissue-specific stem cells are mutually interchangeable. In our experiments, as a model, we used neural stem cells (NSCs) harvested from fetal (E14-15) neocortex and beta-galactosidase positive. In the first experiment we found that on days 12 and 30 after sub-lethal irradiation (LD 8.5 Gy) and (beta-galactosidase(+)) NSCs transplantation all mice survived, just as the group with bone marrow transplantation. Moreover, the bone marrow of mice transplanted NSCs contained the number of CFU-GM colonies with beta-galactosidase(+) cells which was as much as 50% higher. These differences were statistically significant, p<0.001. In the second experiment, we studied kinetics of (beta-galactosidase(+)) NSCs after their transplantation to sub-lethally irradiated mice. Histochemistry of tissues was performed on days 12 and 30 post-transplantation, and beta-galactosidase(+) cells were detected with the help of histochemical examination of removed tissues (lung, liver, spleen, thymus, and skeletal muscle). In tissues removed on day 12 post-transplantation, we found a significantly higher number of beta-galactosidase(+) cells in the spleen and thymus on day 30. While we presumed the presence beta-galactosidase(+) cells in the spleen, as spleen and reticuloendothelial system represent an important retaining system for different cell types, the presence of beta-galactosidase(+) cells in the thymus was rather surprising but very interesting. This indicates a certain mutual and close interconnection of transplanted stem cells and immune system in an adult organism. In the third experiment, we verified the mutual interchange of Sca-1 surface antigen in the bone marrow cells and NSCs before transplantation. Analysis of this antigen showed 24.8% Sca-1 positive cells among the bone marrow cells, while NSCs were Sca-1 negative. Our experiments show that NSCs share hemopoietic identity and may significantly influence the recovery of damaged hematopoiesis but do not have typical superficial markers as HSCs. This result is important for the determination of predictive factors for hemopoiesis recovery, for stem cell plasticity and for their use in the cell therapy.

Animals↗

PubMed2005

Stem cell plasticity and issues of stem cell therapy.

Today, there is much evidence suggesting that organ-specific stem cells need not rely completely on their own sources for maintenance and regeneration of an organism. In certain circumstances, mostly related to tissue damage, stem cell populations residing past the affected organ can contribute to its recovery--that means from different cell lines and also in tissues from another germ layer. The key factor in formation of self-renewing cellular clones is the presence of stem cells either from the tissue of origin or stem cells migrating from other areas and their successful settlement in an empty niche of the damaged tissue. Stem cell plasticity is the ability of adult tissue-specific stem cells to switch to new identities. The term plasticity also means stem cell phenotypic potential, which is broader than phenotypes of differentiated cells in their original tissues. Many laboratories have given evidence on stem cell plasticity; however, the presented results met with many objections from others. In the first part of our report we wish to refer to several issues associated with stem cell plasticity, transdifferentiation and fusion. Recent experimental results show that stem cells will play a key role in cell therapy. But there are still many questions to answer for scientists engaged in stem cell research. Is it possible to induce cells from one type of tissue to look and act as cells of another tissue? Do these changes occur naturally? Could plasticity be used in the treatment of fatal diseases? Cell therapy is one of the methods to treat damaged myocardial tissue. However, recent results with autologous bone marrow cells in the treatment of damaged myocardium show that this method has still many unanswered questions concerning cells, cytokines, microenvironment and other factors responsible for reparation. To date, there are many opinions either recommending or denying this method in different modifications. One question has not yet been definitely solved: What are the conditions for us to accept this method--its safety and efficacy? The future will show whether these our hopes and expectations will be fulfiled. Many experiments are needed before at least some of these questions may be answered and cell therapy become an important method for the benefit of our patients.

Cell Differentiation↗

PubMed2005

Clinical results of intensity-modulated radiation therapy (IMRT) for tumors of the head and neck region.

Intensity-modulated radiation therapy (IMRT) is an advanced form of the three-dimensional conformal radiation therapy (3D-CRT). Highly conformal dose distribution is the basic feature of IMRT. The head and neck region is suitable for this new technology since the primary tumor is often surrounded by several critical structures. IMRT offers the ability of dose escalation due to steep dose gradient towards healthy tissues. In this review, clinical results of IMRT in several head and neck sites are presented, including intracranial tumors. Parotid-sparing strategies and patterns of local-regional failures are analyzed. The possibilities of irradiation of recurrent malignancies are mentioned. In perspective, the potential of IMRT should be explored in conjunction with altered fractionation regimens, including simultaneous integrated boost (SIB). Particularly, studies with dose escalation are desirable.

Brain Neoplasms↗

PubMed2005

[Present view on the stem cell plasticity and cell therapy].

The most controversial problem in the present biology and medicine is the existence of stem cell plasticity. Experimental biology and medicine have been working with stem cells and stem cell therapy more than twenty years. The term plasticity, as it is understood, is the potential of stem cell phenotypes that is much broader that phenotypes of differentiated cells of their original tissues. Many laboratories have documented the existence of stem cell plasticity; however, many objections to the reported results still exist. Here, we present some of these objections questioning the data on stem cell plasticity. We wish to point out some problems associated with plasticity of stem cells, transdifferentiation and cell fusion. Recent experimental results indicate that stem cells may have a key role in stem cell therapy. This review is an introductory discussion on the stem cell plasticity and stem cell therapy.

Animals↗

PubMed2004

Local environmental factors determine hematopoietic differentiation of neural stem cells.

Stem cells exhibit unique properties and hold high therapeutic promise, but factors influencing their differentiation after transplantation need to be recognized and defined for this promise to be fully met. Here, we demonstrate that endogenous colony-forming unit spleen (CFU-S) colonies are not generated in lethally irradiated mice transplanted with neural stem cells obtained from brain tissue of syngeneic donors. We investigated the proportion of transplanted neural stem cells that contributed to hematopoietic reconstitution and compared the distribution of transplanted cells in nonsplenectomized to that of splenectomized mice following sublethal whole-body irradiation. We also used clonogenic assays, colony assays, and histochemical analyses to explore conditions under which transplanted, beta-galactosidase-tagged neural stem cells underwent hematopoietic differentiation. Our results suggest that neural stem cells do undergo extramedullary hematopoiesis, even while no endogenous hematopoietic colonies develop in the spleen. Furthermore, we found that neural stem cells effectively colonized the bone marrow of splectomized recipients. We conclude that the hematopoietic differentiation of neural stem cells is highly dependent on the extramedullary environment. We also conclude that the bone marrow does not provide an environment supportive of hematopoietic differentiation by neural stem cells.

Animals↗

PubMed2004

Nestin expression by newly formed human blood vessels.

Nestin is a type VI intermediate filament protein originally described in neural stem cells. Here we report that immature endothelial cells generated in the course of angiogenesis express nestin. Endothelial cells of embryonic capillaries destined to vascularize growing organs also express this intermediate filament protein. Whereas nestin was sporadically expressed in mature adult human endothelial cells sporadically express nestin, this protein was consistently expressed in adult angiogenic vasculature. Nestin expression was also detected in capillaries of the corpus luteum, which replenishes itself by angiogenesis. Nestin-immunoreactive vessels were also observed in the infarcted hearts where transient ischemia triggered regeneration accompanied with neovascularization of the myocardium. Nestinpositive endothelial cells lined vessels nourishing solid growing tumors, including melanoblastomas and glioblastomas. Our data provide definitive evidence that endothelial precursors express the neural stem cell marker nestin and that this protein participates in formation of the cytoskeleton of newly formed endothelial cells. Because nestin expression was recognized under all conditions of vascular development, nestin represents a novel and reliable marker of neovascularization.

Blood Vessels↗

PubMed2004

Weekly paclitaxel combined with local hyperthermia in the therapy of breast cancer locally recurrent after mastectomy--a pilot experience.

BACKGROUND: The combination of chemotherapy and hyperthermia (HT) is a promising approach in the treatment of malignant tumors. In the present report we evaluate the efficacy and toxicity of a combination of weekly paclitaxel combined with local hyperthermia in breast cancer. PATIENTS AND METHODS: 7 patients were treated for inoperable local recurrence of breast cancer after mastectomy, irradiation, and chemotherapy or hormonal therapy. They weekly received paclitaxel (60-80 mg/m(2)) in 3-h infusions followed by local HT 41-44 degrees C for 45 min for 6-18 cycles. RESULTS: Objective local response was observed in all treated patients (complete response in 4 patients and partial response in 3 patients). There were no grade 3 or 4 toxicities, neurologic toxicity or hypersensitivity reactions. Local tolerance to this regimen was also good, with only 4 patients developing mild transient erythema. CONCLUSION: Our experience indicates that the combination of weekly paclitaxel and HT may be effective in the treatment of locally recurrent breast cancer after mastectomy.

Adenocarcinoma↗

PubMed2003

Adult stem cells and their importance in cell therapy.

For their unique properties stem cells promise to be of universal use in clinical medicine, especially in regeneration of many organs and tissues in the human body. This attractive subject receives an ever growing attention of specialists from different branches of science and, no doubt, will present one of the most studied trends in medicine in the new millennium. In this communication, the authors discuss two main sources of human stem cells potentially suitable for cell-based therapy. The first are the cells obtained from embryonic tissues--embryonic stem cells, the second are the cells derived from adult tissues--adult stem cells. Presently, harvesting and therapeutic use of embryonic stem cells are associated with many problems both methodical and ethical. Utilization of adult stem cells in cell-based therapy is a certain solution in the current state of replacement therapy. Still, we have to be aware that this is not a compromise but one of the most prospective ways to treat a variety of serious diseases. To date, it is not yet clear which way would be more suitable and it is up to us which way we choose for the benefit of millions of patients. Considering the current state of knowledge, it is impossible yet to predict which stem cells--embryonic or adult--or therapeutic approaches would yield the best results. Much research is to be done and verified in practice and, at the same time, ethical problems must be resolved.

Cell- and Tissue-Based Therapy↗

PubMed2002

Antiapoptotic cytokine IL-3 + SCF + FLT3L influence on proliferation of gamma-irradiated AC133+/CD34+ progenitor cells.

Recovery from radiation-induced bone marrow aplasia depends on appropriate cytokine support. The aim of our work was to find a cytokine combination allowing in vitro gamma-irradiated (2.5 Gy) CD34+/AC133+ haematopoietic stem cells to evade radiation-induced apoptosis and to enhance damage reparation, which should enable proliferation and ex vivo expansion of cells. Cells were isolated using separation in a Cobe separator followed by immunomagnetic selection by antibody against the AC133 antigen. Thus isolated cells were 80% AC133+/CD34+ and 10% of them expressed the CD33+ antigen. Ten thousand of AC133+ cells formed 1146 CFU-GM and 304 BFU-E. We proved a high expansion efficiency of cytokine combination SCF + IL-3 + FLT3L in comparison with the combination SCF + IL-3 + IL-11 in both, non-irradiated cells and cells irradiated with a dose of 2.5 Gy. The D0 value for AC133+ cells was determined by the clonogeneity test. The D0 value for CFU-GM was estimated to be 1.08 Gy and for BFU-E 0.95 Gy. The results of DNA analysis showed that the majority of isolated AC133+ cells were in G0/G1 phase of the cell cycle. We proved that the dose of 2.5 Gy induced massive apoptosis (80%) of these cells without progression through the cell cycle, which indicates interphase cell death. Under the influence of cytokine combination (SCF + IL-3 + FLT3L), the surviving 20% of cells entered the cell cycle and, similarly to non-irradiated control cells, on 7th day 35% of cells were in S phase.

Apoptosis↗

PubMed2001

Management of inoperable carcinoma of the breast by curative radiotherapy and chemo-hormonotherapy.

BACKGROUND: The aim of this study was to evaluate local control and its relation to survival in patients with locally advanced breast cancer treated with curative irradiation and systemic therapy. PATIENTS AND METHODS: 240 patients with unresectable breast cancer were treated with curative radio- and chemo- or hormonotherapy from 1990-1995. The frequency of distant dissemination and the overall survival of patients with and without complete local control were compared. RESULTS: Complete local control was achieved in 63% of patients. Complete local control correlated with decrease of distant metastases and increase of survival in comparison with patients without complete local control. CONCLUSION: Radiotherapy without surgery provides insufficient local control in patients with locally advanced breast cancer. Complete local control is an important factor for prevention of distant dissemination and for survival.

Adult↗

PubMed2001

Intensive cyclic chemotherapy with unprocessed whole blood support in advanced breast cancer.

The aim of our project was to compare the efficacy of mobilised whole blood versus cryopreserved PBPC (peripheral blood progenitor cells) obtained by leukapheresis in the support of hematopoietic recovery in cyclic intensive chemotherapy. Twenty-nine women with breast carcinoma were treated. The mean age was 46 years. In stage III were 23, in stage IV were 6. They received 6 cycles of epirubicin 150 mg/m2 and cyclophosphamide 1250 mg/m2. In the first cycle, 24 hours after chemotherapy, application of G-CSF 5 microg/kg/day was started, and discontinued when leukaphereses and whole blood collections were done. Leukapheresed progenitors were then divided into 3 aliquots, cryopreserved and reinfused after the 4th, 5th and 6th chemotherapy cycles. Mobilised whole blood was collected on day 14 of the 1st and 2nd cycles and reinfused 24 hours after chemotherapy. The occurrence of grade IV leukopenia was 1.82 times higher with whole blood support and grade IV thrombocytopenia 2.64 times higher than in cycles with cryopreserved PBPC support. This resulted from the fact that in one application the numbers of CD34+ cells and CFU-GM were nearly double in cryoconcentrates. The yields of CD34+ cells in 450 ml of whole blood were 1.8 x 10(6)/kg, which is not sufficient for optimal hemopoietic recovery.

Adult↗

PubMed2001

Peripheral progenitor cells (PBPC) in supportive care after high-dose chemotherapy in breast cancer.

Hemopoietic growth factors (HGF) and leukapheresed peripheral progenitor cells (PBPC) are increasingly used for supportive care in high-dose chemotherapy (HDC) of solid tumors. Presently, therapeutic protocols with cyclic HDC plus PBPC support are successfuly used in breast cancer patients. Administration of PBPC significantly influences hemopoietic recovery in terms of shortening the pancytopenia period which reduces the risk of dangerous complications, especially the risk of infection. As a certain controversy exists about efficacy of this therapy, large randomized studies are conducted to find more accurate conclusions. In 1998 National Cancer Institute (NCI) gave top priority to four randomized studies of HDC with PBPC support. In recent years, rising yields of PBPC are obtained. The use of new combinations and dosages of hemopoietic growth factors leads to a significant increase of progenitor cells circulating in peripheral blood. Effective mobilization regimens combinations of chemotherapy and cytokines - enable to increase the numbers of circulating progenitors as much as 100-fold. Another aspect, how to minimize the risks is to reduce the transplant volume and so reduce the amount of cryoprotective agent DMSO (dimethyl sulfoxide) and hemolysed erythrocytes. This led to the idea to use only whole blood enriched for PBPC. At present it has been used also in our patients. The results show that enriched whole blood can be used as sufficient substitution for support in intensive cyclic chemotherapy in breast cancer patients.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2000

Application of whole blood and peripheral blood progenitor cells (PBPC) and new strategies for rescue after intensive cyclic chemotherapy in high-risk breast cancer.

The efficacy of autologous peripheral stem cells given as mobilized whole blood or leukapheresis product for hematopoietic rescue after intensive chemotherapy was studied in 34 consecutive female patients with high-risk breast cancer. All patients received six cycles of chemotherapy regimen EC (epirubicin 150 mg/m2 and cyclophosphamide 1250 mg/m2) at 14-day intervals. In the first cycle, chemotherapy was given on day 1, and 24 h later mobilization of PBPC was started with G-CSF at a dose of 5 microg/kg/day for 13 days. In all other cycles, G-CSF was given at the same dose from day 7. On days 11, 12, and 13, leukaphereses were performed, and whole blood was collected on day 14 (the peak incidence of colony-forming units-granulocyte-macrophage [CFU-GM] burst-forming units-erythrocyte [BFU-E], and colony-forming unit-granulocyte-erythrocyte-macrophage-megakaryocyte [CFU-GEMM]). The second cycle of chemotherapy was started on day 15, and 24 h later, whole blood (collected in the first cycle) was reinfused, and the same was done in the third cycle. In the fourth to sixth chemotherapy cycles, leukapheresis product was used for hematopoietic rescue. The median increment of absolute values in both whole blood and leukapheresis product was as follows: CD34+ cells over baseline was approximately 17.4-fold, CFU-GM was 85.3-fold, BFU-E was 95.9-fold, and CFU-GEMM was 44.2-fold. In the cycles with whole blood support, the mean values of applied progenitors per cycle were CD34+ cells 1.52 x 10(6)/kg, CFU-GM, 1.18 x 10(5)/kg, BFU-E 2.54 x 10(5)/kg, CFU-GEMM 0.31 x 10(5)/kg. In the courses with PBPC support, the mean values of progenitors were CD34+ 2.04 x 10(6)/kg, CFU-GM 1.59 x 10(5)/kg, BFU-E 2.87 x 10(5)/kg, and CFU-GEMM 0.34 x 10(5)/kg. Leukopenia in patients supported with whole blood versus leukapheresed PBPC was as follows: grade 4, 13/6 (38.2%/17.6%), grade 3, 19/23 (55.9%/70.6%), and grade 2, 1/4 (2.9%/11.8%), respectively. Thrombocytopenia was grade 4, 11/6 (32.4%/17.6%), grade 3, 10/7 (29.4%/20.6%), grade 2, 7/13 (20.6%/38.2%), and grade 1, 6/6 (17.6%/17.6%), respectively. The median follow-up analysis was at 24.6 (7-36) months. High-risk patients previously treated with surgery and adjuvant chemotherapy (n = 5) were not evaluated for response. In 21 patients with locally advanced or inflammatory breast carcinoma the response rate (RR) was 94%, CR was 90%, and PR was 15%. No response to therapy was observed in 1 patient. In 8 patients with metastatic disease, RR was 75%, there was no CR, and PR was 75%. Two patients died during therapy. Relapse-free survival (RFS) in the adjuvant group was 23.7 (range 12-36) months and in the group with locally advanced disease was 18.2 (range 7-27) months. In the group with metastatic disease, time to tumor progression (TTP) was 12.1 (range 1-16) months. Mean duration of hospital stay for whole blood reinfusion in the second and third chemotherapy cycles was 6.7 (range 5-8) days and for PBPC in the fourth to sixth cycles was 6.2 (range 4-8) days, which at p < 0.001 was not statistically significant.

Adult↗

PubMed2000

Myeloid differentiation and maturation of SCF+IL-3+IL-11 expanded AC133+/CD34+ cells selected from high-risk breast cancer patients.

The AC133 antigen is selectively expressed on subset of CD 34+ cells isolated from leukapheresis products from high risk breast cancer patients receiving chemotherapy plus G-CSF. MiniMACS AC133+ isolated cells contained a mean of 85% (80-90) AC133+ cells. Enriched AC133+ cells coexpressed 80% CD34+, 6.6% CD33+ and 2% CD15+. Separated AC133+ cells contained 600 GFU-GM/10(4) cells and 70 BFU-E/10(4) cells. Flow-cytometric analysis indicated that AC133+ cells were isolated from cells population with low granularity (SS), while CD33+ a CD15+ cells had a high granularity. After a seven-day ex vivo expansion in the presence of SCF + IL-3 + IL11, the expansion of cells increased 19.4 times. The mean percentage of blasts decreased from 100% at the start of culture to 81% on day 3 and 30% on day 7. Promyelocytes were slow to appear with 10% present on day 3, but thereafter increased to 33% on day 7. The appearance of myelocytes and metamyelocytes lagged 3 days behind promyelocytes and continued to increase during culture to become the predominant (30%) cell type on day 7. Very few neutrophils (2%) were observed in any of the cultures on day 7. Monocytes or macrophages were not detected on day 7. By day 7 megakaryocytes were present at low levels (10%). The mean value of CFU-GM in the culture after day 7 of ex vivo expansion in the presence of SCF+IL-3+IL-11 had increased 45-fold, BFU-E 5-fold. After 7 days of expansion with IL-3+SCF+IL-11 cells expressed a mean of 12% CD34+, 8% AC133+, 59% CD33+ and 30% CD15+. The aim of this experiment was to determine whether ex vivo culture of peripheral blood AC133+ cells could generate sufficient numbers of progenitors to potentially abrogate cytopenia after transplantation and passive purging of tumor cells.

AC133 Antigen↗

PubMed2000

The role of chemotherapy in prostate cancer. Minireview.

Hormonal therapy in disseminated prostate cancer is effective in 70-80% of patients and prolongs their lives of a mean 1-2 years. Sooner or later, androgen independence develops due to a multifactorial mechanism. A smaller part of patients may respond to second-line hormonal manipulations (antiandrogen withdrawal, adrenal enzymes synthesis inhibitors, corticosteroids). In hormone-refractory disease only about 30% of patients would respond to chemotherapy. In the standard chemotherapy the mostly used cytotoxic agents are anthracyclines, platinum derivatives, vinca alkaloids and cyclophosphamide. However, combined chemotherapy is not more effective than monotherapy. Conventional chemotherapy may improve especially the quality of life. The median survival in chemotherapy patients (6-12 months) is not significantly longer when compared with the best supportive care. In recent years the main concern has been focused on new cytotoxic drugs and different combinations with hormonal agents. In Phase II studies the combinations of estramustine with oral etoposide, estramustine with taxanes and alternating weekly regimens (doxorubicin, ketoconazole/estramustine, vinblastine) show higher response rates (53-69% of patients with prostate-specific antigen decline of more than 50%) and longer survival (13-19 months) than conventional chemotherapy.

Antineoplastic Agents, Hormonal↗

PubMed2000

The current look at high-dose chemotherapy in breast cancer minireview.

High-dose chemotherapy (HDC) in high-risk breast cancer is one of the possible approaches how to improve therapeutic results, eventually, to overcome the incurability of the disease. In recent randomized studies superiority of HDC to conventional therapy has not been unambiguously established. Nevertheless, many oncologists, as well as, patients are so convinced of HDC benefits, that they are not willing to take part in randomized studies. At an ASCO Annual Meeting (American Society of Clinical Oncology) in May 1999 in Atlanta - preliminary results of five large randomized studies phase III were presented (2 studies on metastatic breast cancer and 3 studies on high-risk breast cancer with more than 10 positive lymph nodes). The ASCO was informed of an investigation into serious scientific misconduct in a clinical trial that was presented in a plenary session of its Annual Meeting. The results of Dr. Bezwoda's research were presented at ASCO's Meeting as one of four plenary papers on the investigational therapy and was the only one to clearly indicate a survival benefit in the high-dose regimen. Preliminary results presented there, however, did not confirm the original hypothesis of the high efficacy of HDC. It is necessary to wait for definite results (within two or three years, because enrollment of patients either has been finished or is being finished just now) and several parameters may change. In view of hitherto results, some investigators think that there is no need to continue in similar intensive studies. Still some believe that different modifications of therapeutic regimens or new, less toxic drugs should be tested which may lead to more effective and safer HDC.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1999

Ex vivo expansion CD34+/AC133+-selected autologous peripheral blood progenitor cells (PBPC) in high-risk breast cancer patients receiving intensive chemotherapy.

AC133 antibody provides an alternative to CD34 for the selection and characterization of cells necessary for engraftment in transplant situations. We studied the effect of stem cell factor (SCF), interleukin 3 (IL-3) and interleukin 11 (IL-11) on the ex vivo expansion of human CD34+/AC133+ progenitors isolated from leukapheresis products from chemotherapy plus granulocyte-colony-stimulating factor (G-CSF) -mobilized adult donors. MiniMACS AC133+ isolated cells contained a mean of 85% (80-90) AC133+ cells. Enriched AC133+ cells co-expressed CD34+ 80%, CD71low 36.6% and CD33+ 6.6%. After a seven-day ex vivo expansion in the presence of SCF + IL-3 + IL-11, the number of cells increased 19 times. These cells expressed a mean 12% CD34+ and 74% CD71+ (23% CD 71high) and 59% CD33+. This means that the absolute number of CD34+ cells increased slightly, the number of CD33+ increased 100 times and cells with high density CD71high (23%) appeared. These cells represent the cells committed to erythroid differentiation. The increase in the number of CFU-GM with various combinations of cytokines SCF + Il-3 + IL-11 will be discussed. The number of CFU-GM in culture after a seven-day ex vivo expansion in the presence of SCF + IL-3 + IL-11 increased 45 times.

AC133 Antigen↗