Biomedical subjects

Piero Picci

Publications and source records attributed to Piero Picci.

At least 19 recordsLinked to original sources

PubMed2007

Adjuvant and neoadjuvant chemotherapy for Ewing sarcoma family tumors in patients aged between 40 and 60: report of 35 cases and comparison of results with 586 younger patients treated with the same protocols in the same years.

BACKGROUND: The clinical and pathologic features of 46 patients 40 to 60 years old with Ewing sarcoma family tumor (ESFT) diagnosed at the authors' institute between 1972 and 2000 were reviewed. METHODS: Ten patients with metastatic tumors at presentation went elsewhere for treatment; 35 of 36 remaining cases with localized disease were treated at the authors' institution according to different chemotherapy protocols activated in successive years. In patients with nonmetastatic tumors local treatment was surgery in 9 patients, radiotherapy in 16, and surgery followed by radiotherapy in 10. RESULTS: At follow-up times ranging from 6 and 34 years (mean, 17.8 years), 15 patients (42.9%) remained continuously disease-free, 19 experienced recurrence, and 1 died of chemotherapy-related toxicity. The 5- and 10-year event-free survivals were 42.9% and 35.2%, respectively, and the 5- and 10-year overall survivals were 46.1% and 42.8%, respectively. Comparing this group of patients with 586 cases of younger patients seen in the same period at Rizzoli, the only difference between the 2 groups was a significantly higher rate of tumors located in the soft tissues with a larger volume in the older group. The results achieved were comparable in the 2 groups, although the older group had a lower chemotherapy dose-intensity and a higher rate of WHO grade 4 hematologic toxicity. CONCLUSIONS: For patients with localized disease treated with adjuvant and neoadjuvant chemotherapy the results were essentially comparable in the 2 groups. It is concluded that patients 40 years or older with ESFT should be treated in the same way as younger patients and included in treatment trials for these tumors.

Adult↗

PubMed2006

Neoadjuvant chemotherapy for radioinduced osteosarcoma of the extremity: The Rizzoli experience in 20 cases.

PURPOSE: Evaluate treatment and outcome of 20 patients with radioinduced osteosarcoma (RIO). Because of previous primary tumor treatment, RIO protocols were different from others we used for non-RIO. PATIENTS AND METHODS: Between 1983 and 1998, we treated 20 RIO patients, ages 4-36 years (mean 16 years), with chemotherapy (two cycles before surgery, three postoperatively). The first preoperative cycle consisted of high-dose Methotrexate (HDMTX)/Cisplatinum (CDP)/Adriamycin (ADM) and the second of HDMTX/CDP/Ifosfamide (IFO). The three postoperative treatments were performed with cycles of MTX/CDP; IFO was used as single agent per cycle repeated three times. RESULTS: Two patients received palliative treatment because their osteosarcoma remained unresectable after preoperative chemotherapy. The remaining 18 patients had surgery (7 amputations, 11 resections); histologic response to preoperative chemotherapy was good in 8 patients, poor in 10. At a mean follow-up of 11 years (range, 7-22 years), 9 patients remained continuously disease-free, 10 died from osteosarcoma and 1 died from a third neoplasm (myeloid acute leukemia). These results are not significantly different from those achieved in 754 patients with conventional osteosarcoma treated in the same period with protocols used for conventional treatment. However, this later group had an 18% 3-year event-free survival after treatment of relapse vs. 0% in the RIO group. CONCLUSION: Treated with neoadjuvant chemotherapy RIO seem to have an outcome that is not significantly different from that of comparable patients with conventional primary high grade osteosarcoma (5-year event-free survival: 40% vs. 60%, p = NS; 5-year overall survival 40% vs. 67%, p < 0.01).

Adolescent↗

PubMed2006

Growth inhibition and sensitization to cisplatin by zoledronic acid in osteosarcoma cells.

Since osteosarcoma is a drug-resistant disease, the aim of the present study was to explore the possible interest of therapeutic approaches including nitrogen-containing biphosphonate zoledronic acid using osteosarcoma cell lines with different genetic backgrounds. Parental p53+/pRb+ U2-OS, p53-mutant U2-OS (U2-OS/175) and p53-/pRb- SAOS were sensitive to zoledronic acid with no significant differences in IC50 values. Analysis of cell cycle distribution revealed a time-dependent shifting of U2-OS cells towards G2 phase with cell cycle arrest in G2 phase at 96 h of exposure to the compound. Conversely, U2-OS/175 and SAOS cells responded to treatment with transient cell accumulation in S phase up to 48-72 h, respectively. Cell lines were exposed to increasing concentrations of cisplatin alone or combined with sub-toxic doses of zoledronic acid. A growth inhibitory effect was seen after combined treatment in U2-OS, otherwise resistant to cisplatin up to 100 ng/ml. Zoledronic acid did not efficiently sensitized U2-OS/175 and SAOS to cisplatin, thereby suggesting that different behavior may depend on p53 mutation. This data was confirmed in U2-OS cells where p53 expression was downregulated by RNA interference. Present findings indicate occurrence of sensitization to cisplatin by zoledronic acid in wild-type p53 osteosarcoma cells but not in p53-null cells nor in cells expressing a dominant-negative form of p53, supporting that wild-type p53 is required for synergistic interaction of cisplatin and zoledronic acid.

Antineoplastic Agents↗

PubMed2006

Insulin-like growth factor binding protein 3 as an anticancer molecule in Ewing's sarcoma.

The IGF/IGF-IR system plays a major role in the pathogenesis and progression of Ewing's sarcoma. In this article, the authors evaluated whether the insulin-like growth factor binding protein-3 (IGFBP-3), a molecule with growth-inhibitory and proapoptotic activities, may be exploited for therapeutic applications in the treatment of Ewing's sarcoma (EWS). Expression of IGFBP-3 was analyzed in a panel of EWS cell lines and clinical samples. Parameters related to malignancy (growth in anchorage-independent conditions, migration, invasion and angiogenesis properties) were studied to establish the potential in vitro anticancer effects of exogenous IGFBP-3. The activity of the molecule against metastasis was analyzed by taking advantage of selected clones in which IGFBP-3 endogenous production was induced by gene transfection. The authors observed a generally low expression of IGFBP-3 either in a panel of EWS cell lines or clinical samples. Exogenous IGFBP-3 remarkably inhibits EWS growth, both in monolayer and anchorage-independent conditions, and significantly reduces cell motility. Forced expression of IGFBP-3 in TC-71 EWS cells confirms the growth and migratory effects observed with the exogenous protein, decreases the production or activity of the matrixmetalloprotease MMP-9 and vascular endothelial factor (VEGF)-A and abrogates EWS metastasis ability. IGFBP-3 acts mainly through IGF-dependent mechanisms and the protein may therefore represent an alternative strategy to inhibit IGF-IR functions. The data indicate IGFBP-3 as a molecule of therapeutic potential in EWS.

Animals↗

PubMed2006

Malignant fibrous histiocytoma of bone: analysis of genomic imbalances by comparative genomic hybridisation and C-MYC expression by immunohistochemistry.

Malignant fibrous histiocytoma (MFH) of bone is a rare, highly malignant tumour. As very little is known about its genetic alterations, 26 bone MFHs were analysed by comparative genomic hybridisation (CGH). Twenty-three tumours (89%) had DNA sequence copy number changes (mean, 7.2 changes per sample). Gains were more frequent than losses (gains:losses=2.5:1). Minimal common regions for the most frequent gains were 8q21.3-qter (35%), 9q32-qter (35%), 7q22-q31 (35%), 1q21-q23 (31%), 7p12-pter (31%), 7cen-q11.2 (31%) and 15q21 (31%). Minimal common regions for the most frequent losses were 13q21-q22 (42%) and 18q12-q22 (27%). High-level amplifications were detected in 8 out of the 26 tumours (31%). The only recurrent amplifications, 1q21-q23 and 8q21.2-q22, were present in two samples (8%). As copy number increase at 8q24 (the locus of C-MYC) was frequent, the expression of C-MYC was studied by immunohistochemistry. Increased levels of c-myc protein were detected in 7 out of 21 tumours studied (33%). 81% of the samples studied both by CGH and immunohistochemistry showed concordant results. Furthermore, the findings of the present study were compared to previous publications on osteosarcoma, soft tissue MFH and fibrosarcoma of bone. Clear differences were detected in CGH aberration patterns, further supporting the concept of bone MFH as an individual bone tumour entity. Finally, the findings of the present study reflect well the high malignancy and aggressive nature of bone MFH.

Adolescent↗

PubMed2006

The role of surgical margins in treatment of Ewing's sarcoma family tumors: experience of a single institution with 512 patients treated with adjuvant and neoadjuvant chemotherapy.

PURPOSE: To evaluate the importance of surgical margins for local and systemic control of Ewing's sarcoma family tumors (ESFT). METHODS AND MATERIALS: Between 1979 and 1999, 512 patients with ESFTs entered 4 different adjuvant and neoadjuvant studies performed at a single institution. Of these patients, 335 were treated with surgery alone (196) or surgery followed by radiotherapy at doses of 44.8 Gy (139). We compared their outcome with that of the 177 patients who were locally treated by radiotherapy at 60 Gy. RESULTS: Local control (88.8% vs. 80.2%, p < 0.009) and 5-year disease-free survival (63.8% vs. 47.6%, p < 0.0007) were significantly better in patients treated with surgery and, among them, in those with adequate surgical margins (96.6% vs. 71,7%, p < 0.0008, and 69.6% vs. 46.3%, p < 0.0002). Nonetheless, better results were observed only in extremity tumors. CONCLUSIONS: Surgery is better than radiotherapy in cases of extremity ESFT with achievable adequate surgical margins, and in cases of inadequate surgical margins, adjuvant reduced-dose radiotherapy is ineffective. Therefore, when inadequate margins are expected, patients are better treated with full-dose radiotherapy from the start.

Adolescent↗

PubMed2006

Prognostic factors for osteosarcoma of the extremity treated with neoadjuvant chemotherapy: 15-year experience in 789 patients treated at a single institution.

BACKGROUND: The evaluation variables influencing systemic and local recurrence and final outcome are extremely important in defining risk-adapted treatments for patients with nonmetastatic osteosarcoma of the extremity. METHODS: A homogeneous group of 789 patients treated at a single institution between March 1983 and March 1999 with different protocols of neoadjuvant chemotherapy, with a minimum followup of 5 years, were retrospectively evaluated in relation to gender, age, serum levels of alkaline phosphatase, tumor site and size of the pathologic fracture, type of surgery, protocol of chemotherapy, surgical margins, and histologic response to preoperative treatment. RESULTS: The 5-year event-free survival (EFS) and overall survival rates were 60.1% and 67.5%, respectively. Upon univariate analysis, EFS was significantly related to the age of patients, serum value of alkaline phosphatase, tumor volume, histologic subtype, type of surgery, surgical margins, histologic response to preoperative treatment, and chemotherapy protocol. Local recurrences (4.8%) were significantly correlated with surgical margins. The 5-year post-recurrence EFS survival was 17% and was significantly lower for patients who had a local recurrence and metastases than for those with metastases only. Patients who had a recurrence only in the lung had a post-recurrence survival rate significantly better than others, correlated with the number of metastatic nodules and the length of the disease-free interval. CONCLUSIONS: Upon multivariate analysis, age < or = 14 years, high serum levels of alkaline phosphatase, tumor volume > 200 mL, a two-drug regimen chemotherapy, inadequate surgical margins, and poor histologic response to treatment maintained independent prognostic values on the outcome of nonmetastatic osteosarcoma of the extremities. These factors must be considered when deciding risk-adapted treatments for osteosarcoma patients.

Adolescent↗

PubMed2006

Chordoma of the mobile spine: fifty years of experience.

STUDY DESIGN: A consecutive series of 52 chordomas of the mobile spine observed over a 50-year period includes a retrospective review of 15 cases treated prior to 1991 and a prospective group of 37 cases treated from 1991 to 2002. OBJECTIVES: This series reviews epidemiologic issues as well as clinical patterns of spinal chordomas. We attempt to correlate tumor extent, treatment, and outcomes over time. SUMMARY OF BACKGROUND DATA: Chordoma is the most frequent primary tumor of the mobile spine. Due to slow growth, both initial symptoms and recurrences after treatment arise later, making it difficult to evaluate the effectiveness of treatment protocols. METHODS: A prospective series of 37 cases is compared with a retrospective group of 15 patients observed between 1954 and 1991. In the prospective study, all patients had imaging studies, and oncologic and surgical staging. When en bloc resection was not feasible, intralesional extracapsular excision was combined with radiation therapy. The prospective patients were clinically evaluated and imaged. Patients in the retrospective group were evaluated by chart and available images; of these, only one en bloc resection (intralesional margin) was performed. Survivors were all evaluated clinically and had radiographic studies. RESULTS: Forty-eight patients were available for long-term follow-up. Four died due to post-operative complications, and six due to disease less than 2 years after treatment. Forty-two patients were followed over 2 years; 26 patients had over 5 years follow-up. All patients having radiation alone, intralesional excision, or a combination had recurrences in less than 2 years, and died in some cases after a long survival with symptomatic disease. Intralesional extracapsular excision with radiation had a high rate of recurrence (12 of 16 at average 30 months), but 3 patients are continuously disease-free (CDF) at mean 52 months and 5 are alive with disease at average 69 months (ranging 24 to 146). Twelve of 18 patients having en bloc resection are CDF at average 8 years (48 to 155 months). The remaining 6 recurred and of these 1 died. All of these (6) had been previously treated and/or had en bloc resections with contaminated margins. CONCLUSIONS: The only treatment protocol associated with CDF at follow-up longer than 5 years is margin-free en bloc resection.

Adult↗

PubMed2006

Alpha-tocopheryl succinate alters cell cycle distribution sensitising human osteosarcoma cells to methotrexate-induced apoptosis.

alpha-Tocopheryl succinate (alpha-TOS) exerts pleiotrophic responses in malignant cells leading to cell cycle arrest, differentiation and apoptosis. We tested the ability of alpha-TOS to induce apoptosis or cell cycle perturbation in three human osteosarcoma (OS) cell lines which differ in their pRB and p53 status. We found high levels of apoptosis in OS cells carrying wild-type p53 gene when exposed to alpha-TOS, while the mutant p53 cells were resistant. A S/G2 transition arrest was observed in two OS cell lines exposed to alpha-TOS, which sensitised them to methotrexate, an agent whose activity is cell cycle-dependent. We propose that alpha-TOS may be used as a drug or an adjuvant for treatment of osteosarcomas.

Apoptosis↗

PubMed2006

CD99 acts as an oncosuppressor in osteosarcoma.

CD99 was recently reported to be under control of the osteoblast-specific transcription factor Cbfa1 (RUNX2) in osteoblasts, suggesting a role in the phato-physiology of these cells. No extensive information is available on the role(s) of this molecule in malignant phenotype, and osteosarcoma, in particular, has never been studied. We report that in 11 different cell lines and 17 clinical samples CD99 expression is either undetectable or very low. Being expressed in the normal counterpart, we tested the hypothesis that CD99 down-regulation may have a role in osteosarcoma development and progression. CD99-forced expression in two osteosarcoma cell lines significantly reduced resistance to anoikis, inhibited growth in anchorage independence as well as cell migration, and led to abrogation of tumorigenic and metastatic ability. Therefore, the molecule acts as a potent suppressor of malignancy in osteosarcoma. CD99 gene transfection induces caveolin-1 up-regulation and the two molecules were found to colocalize on the cell surface. Treatment with antisense oligonucleotides to caveolin-1 abrogates the effects of CD99 on migration. The findings point to an antioncogenic role for CD99 in osteosarcoma, likely through the regulation of caveolin-1 and inhibition of c-Src kinase activity.

12E7 Antigen↗

PubMed2006

No correlation between methotrexate serum level and histologic response in the pre-operative treatment of extremity osteosarcoma.

Our objectives were to evaluate the behavior of different doses of pre-operative methotrexate (MTX) pharmacokinetics, and assess correlations between the osteosarcoma histologic response and MTX serum peak concentrations. In total, 336 patients with osteosarcoma of the extremities were treated with three neoadjuvant protocols of chemotherapy including high-dose MTX (different doses for each protocol), cisplatin and doxorubicin (same doses in all protocols). The doses of MTX were 8 g/m2 in 124 patients, 10 g/m2 in 110 patients and 12 g/m2 in 102 patients. The mean value of peak serum MTX was 801 micromol/l (range 298-1831) with significant intra- and inter-patient variability. For patients treated with 8, 10 and 12 g/m2 it was 587, 735 and 1114 micromol/l, respectively (P < 0.0001). The histologic response to pre-operative chemotherapy was 90% or above tumor necrosis in 62.8% of patients and less than 90% in 37.2%. The grade of histologic response significantly correlated with the histologic subtype of the tumor, whereas no significant association was found between the mean peak of serum MTX and the histologic response. Thus, increasing the dose of MTX increases the MTX serum peaks, but does not correlate with the histologic response of the tumor.

Adolescent↗

PubMed2006

Second malignant neoplasm in patients with osteosarcoma of the extremities treated with adjuvant and neoadjuvant chemotherapy.

We evaluated the rate of second malignancies in 1205 patients with osteosarcoma of the extremity treated at our Institution with different protocols of adjuvant and neoadjuvant chemotherapy. Twenty-six patients (2.15%) developed a second malignant neoplasm at a median of 7.6 years (1 to 25 y) after primary osteosarcoma treatment. Of these, 2 developed a third cancer which were not considered in the series. Second neoplasms were leukemia (10), breast (7), lung (2), kidney (2), central nervous system cancer (2), soft tissue (1), parotid (1), and colon (1). The rate of second neoplasms was significantly higher in female patients, and the latent period shorter in hematologic tumors compared with solid tumors. Ten of these 26 patients are disease free at a median of 7.7 years (range 1 to 15 y) after the last treatment. The rate of second malignancies observed in the osteosarcoma group was significantly higher than that observed in the control group of 1160 patients with benign tumors treated in the same period at our Institute (2.2% vs. 0.8%, P<0.009). Our study showed that the risk of second neoplasm within 15 years increased and then leveled off and that although secondary solid tumors could be explained as unrelated cases, leukemias seem to be over represented.

Adolescent↗

PubMed2006

May P-glycoprotein status be used to stratify high-grade osteosarcoma patients? Results from the Italian/Scandinavian Sarcoma Group 1 treatment protocol.

The aim was to evaluate the clinical impact of P-glycoprotein in primary non-metastatic high-grade osteosarcoma patients, treated with neoadjuvant chemotherapy protocols. P-glycoprotein was assessed by immunohistochemistry on paraffin-embedded tissue samples collected at time of diagnosis from 94 osteosarcoma patients, treated with the Italian Sarcoma Group/Scandinavian Sarcoma Group 1 (ISG/SSG 1) protocol. P-glycoprotein-positivity at diagnosis was found in 53/94 ISG/SSG 1 cases (56%) and emerged as the single factor significantly associated with an unfavourable outcome from survival and multivariate analyses. A comparative analysis of the subgroup of 94 patients considered for P-glycoprotein evaluation and the whole series of ISG/SSG 1 patients showed that this marker retained its prognostic value also in the latter group. In osteosarcoma patients treated with doxorubicin-based chemotherapy protocols, P-glycoprotein overexpression at diagnosis is an important adverse prognostic factor for outcome. P-glycoprotein evaluation can therefore constitute the basis for stratifying, at diagnosis, osteosarcoma patients for whom alternative treatments may be considered.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2005

Targeting CD99 in association with doxorubicin: an effective combined treatment for Ewing's sarcoma.

CD99 is a 32kDa surface glycoprotein that is involved in the migration of leukocytes, cell-cell adhesion and apoptosis of T cells and Ewing's sarcoma (ES) cells, two cell types with a high level of CD99 expression. Engagement of the molecule induces a rapid death signal that appears to be related to the level of expression of this antigen. The rapid apoptosis induced by agonistic anti-CD99 monoclonal antibodies is of clinical interest in ES, a tumour for which no new drugs have been described as clearly effective in the last 10 years. In this study, we show that an anti-CD99 monoclonal antibody can be used to advantage in association with doxorubicin. Striking effectiveness was observed against local tumours and metastases. No remarkably toxic effects of anti-CD99 monoclonal antibody were found in bone marrow against blood precursors. These results provide the necessary rationale and support for a novel modality of therapeutic intervention, which may have application in the care of patients with ES.

12E7 Antigen↗

PubMed2005

Adjuvant and neoadjuvant chemotherapy for osteosarcoma of the extremities: 27 year experience at Rizzoli Institute, Italy.

Around 1148 patients with non-metastatic osteosarcoma of the extremity were treated in a single institution between 1972 and 1999 with 4 different protocol of adjuvant and 7 different protocols of neoadjuvant chemotherapy. The rate of limb salvage increased from 20% to 71%. The 5-year event-free survival (EFS) and overall survival (OS) were 57% and 66%, respectively. The 10-year EFS and OS were 52% and 57%, respectively, and the results significantly correlated with serum alkaline phosphatase levels; the type of chemotherapy (adjuvant vs neoadjuvant); and with histologic response to pre-operative treatment. Aggressive chemotherapy and surgery could cure about the 60% of patients with osteosarcoma of the extremity. However, since local or systemic relapses, myocardiopathies and a second malignancy are possible even 5 or more years since the beginning of treatment, a long-term follow-up is recommended.

Adolescent↗

PubMed2005

Neoadjuvant chemotherapy with high-dose Ifosfamide, high-dose methotrexate, cisplatin, and doxorubicin for patients with localized osteosarcoma of the extremity: a joint study by the Italian and Scandinavian Sarcoma Groups.

PURPOSE: To explore the effect of high-dose ifosfamide in first-line treatment for patients < or = 40 years of age with nonmetastatic osteosarcoma of the extremity. PATIENTS AND METHODS: From March 1997 to September 2000, 182 patients were evaluated. Primary treatment consisted of two blocks of high-dose ifosfamide (15 g/m2), methotrexate (12 g/m2), cisplatin (120 mg/m2), and doxorubicin (75 mg/m2). Postoperatively, patients received two cycles of doxorubicin (90 mg/m2), and three cycles each of high-dose ifosfamide, methotrexate, and cisplatin (120 to 150 mg/m2). Granulocyte colony-stimulating factor support was mandatory after the high-dose ifosfamide/cisplatin/doxorubicin combination. RESULTS: No disease progression was recorded during primary chemotherapy, 164 patients (92%) underwent limb-salvage surgery, four patients (2%) underwent rotation plasty, and 11 patients (6%) had limbs amputated. Three (1.6%) patients died as a result of treatment-related toxicity, and one died as a result of pulmonary embolism after pathologic fracture. Grade 4 neutropenia and thrombocytopenia followed 52% and 31% of all courses, respectively, and mild to severe nephrotoxicity was recorded in 19 patients (10%). The median received dose-intensity compared with protocol was 0.82. With a median follow-up of 55 months, the 5-year probability of event-free survival was 64% (95% CI, 57% to 71%) and overall survival was 77% (95% CI, 67% to 81%), whereas seven patients (4%) experienced local recurrence. CONCLUSION: The addition of high-dose ifosfamide to methotrexate, cisplatin, and doxorubicin in the preoperative phase is feasible, but with major renal and hematologic toxicities, and survival rates similar to those obtained with four-drug regimens using standard-dose ifosfamide. Italian Sarcoma Group/Scandinavian Sarcoma Group study I showed that in a multicenter setting, more than 90% of patients with osteosarcoma of the extremity can undergo conservative surgery.

Adolescent↗

PubMed2005

In Ewing's sarcoma CCN3(NOV) inhibits proliferation while promoting migration and invasion of the same cell type.

Altered expression of CCN3 has been observed in a variety of musculoskeletal tumours, including Ewing's sarcoma (ES). Despite its widespread distribution, very little is known about its biological functions and molecular mechanisms of action. We transfected CCN3 gene into a CCN3-negative ES cell line and analysed the in vitro and in vivo behaviours of stably transfected clones. Forced expression of CCN3 significantly reduced cell proliferation in vitro, growth in anchorage-independent conditions, and tumorigenicity in nude mice. Despite the antiproliferative effect, CCN3-transfected ES cells displayed increased migration and invasion of Matrigel. The decreased expression of alpha2beta1 integrin receptor and the increased amount of cell surface-associated matrix metalloproteinase (MMP)-9 following the expression of CCN3 may be the basis for the increased migratory abilities of transfected cells. Cells lacking alpha2beta1 are less facilitated to have stable anchorage since the predominant collagen extracted from ES tissue is indeed type I collagen, and proMMP-9 was recently found to provide a cellular switch between stationary and migratory ES cell phase. Our findings are in line with those recently obtained in glioblastoma. However, the underlying molecular mechanisms appear to be different, further highlighting the importance of the cellular context in the regulation of function of CCN proteins.

Animals↗

PubMed2005

Alpha-tocopheryl succinate induces cytostasis and apoptosis in osteosarcoma cells: the role of E2F1.

Alpha-tocopheryl succinate (alpha-TOS), a redox-inactive analog of vitamin E, induces cell cycle arrest, differentiation, and triggers apoptosis. We examined the ability of alpha-TOS to induce cytostasis and/or apoptosis in two human osteosarcoma cell lines, which carry wild-type pRb but differ in the p53 status. In the wt-p53 cells, alpha-TOS induced apoptosis, which was associated with p53 activation and enhanced E2F1 expression. Mutant p53 cells failed to undergo apoptosis when challenged with alpha-TOS. The cell growth arrest after alpha-TOS treatment was associated with a reduced expression of E2F1. Knocking down E2F1 rendered the alpha-TOS-sensitive cells rather resistant to the apoptotic stimulus inducing a marked and prolonged cell growth arrest. We conclude that alpha-TOS induces cell growth arrest or apoptosis involving E2F1.

Apoptosis↗