Carmen Pacilio

Latest developments in gene transfer technology: achievements, perspectives, and controversies over therapeutic applications.

Over the last decade, more than 300 phase I and phase II gene‐based clinical trials have been conducted worldwide for the treatment of cancer and monogenic disorders. Lately, these trials have been extented to the treatment of AIDS and, to a lesser extent, cardiovascular diseases. There are 27 currently active gene therapy protocols for the treatment of HIV‐1 infection in the USA. Preclinical studies are currently in progress to evaluate the possibility of increasing the number of gene therapy clinical trials for cardiopathies, and of beginning new gene therapy programs for neurologic illnesses, autoimmuno diseases, allergies, regeneration of tissues, and to implement procedures of allogeneic tissues or cell transplantation. In addition, gene transfer technology has allowed for the development of innovative vaccine design, known as genetic immunization. This technique has already been applied in the AIDS vaccine programs in the USA. These programs aim to confer protective immunity against HIV‐1 transmission to individuals who are at risk of infection. Research programs have also been considered to develop therapeutic vaccines for patients with AIDS and generate either preventive or therapeutic vaccines against malaria, tuberculosis, hepatitis A, B and C viruses, influenza virus, La Crosse virus, and Ebola virus. The potential therapeutic applications of gene transfer technology are enormous. However, the effectiveness of gene therapy programs is still questioned. Furthermore, there is growing concern over the matter of safety of gene delivery and controversy has arisen over the proposal to begin in utero gene therapy clinical trials for the treatment of inherited genetic disorders. From this standpoint, despite the latest significant achievements reported in vector design, it is not possible to predict to what extent gene therapeutic interventions will be effective in patients, and in what time frame.

GENE TRANSFER TECHNOLOGY IN THERAPY : CURRENT APPLICATIONS AND FUTURE GOALS

Gene therapy has attracted much interest since the first submissions of phase I clinical trials in the early 1990s, for the treatment of inherited genetic diseases. Preliminary results were very encouraging and prompted many investigators to submit protocols for phase I and phase II clinical trials for the treatment of inherited genetic diseases and cancer. The possible application of gene transfer technology to treat AIDS, cardiopathies, and neurologic diseases is under evaluation. Some viral vectors have already been used to deliver HIV‐1 subunits to immunize volunteers who are participating in the AIDS vaccine programs in the USA. However, gene delivery systems still need to be optimized in order to achieve effective therapeutic interventions. The purpose of this review is to summarize the latest achievements in improving gene delivery systems, their current application in preclinical studies and in therapy, and the most pressing issues that must be addressed in the area of vector design.

Adenoviral RB2/p130 Gene Transfer Inhibits Smooth Muscle Cell Proliferation and Prevents Restenosis After Angioplasty

Smooth muscle cell (SMC) proliferation that results in neointima formation is implicated in the pathogenesis of atherosclerotic plaques and accounts for the high rates of restenosis that occur after percutaneous transluminal coronary angioplasty, a widespread treatment for coronary artery disease. Endothelial lesions trigger intense proliferative signals to the SMCs of the subintima, stimulating their reentry into the cell cycle from a resting G(0) state, resulting in neointima formation and vascular occlusion. Cellular proliferation is negatively controlled by growth-regulatory or tumor-suppressor genes, or both, such as the retinoblastoma gene family members (RB/p105, p107, RB2/p130). In the present study, we show that RB2/p130 inhibited SMC proliferation in vitro and in vivo. We used the rat carotid artery model of restenosis to demonstrate that adenovirus-mediated localized arterial transduction of RB2/p130 at the time of angioplasty significantly reduced neointimal hyperplasia and prevented restenosis. Furthermore, the ability of pRb2/p130 to block proliferation correlated with its ability to bind and sequester the E2F family of transcription factors, which are important mediators of cell cycle progression. These results imply that RB2/p130 could be an important target for vascular gene therapy.

Endocrine Effects of Adjuvant Letrozole Compared With Tamoxifen in Hormone-Responsive Postmenopausal Patients With Early Breast Cancer: The HOBOE Trial

PURPOSE We compared the endocrine effects of 6 and 12 months of adjuvant letrozole versus tamoxifen in postmenopausal patients with hormone-responsive early breast cancer within an ongoing phase III trial. PATIENTS AND METHODS Patients were randomly assigned to receive tamoxifen, letrozole, or letrozole plus zoledronic acid. Serum values of estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, dehydroepiandrosterone-sulphate (DHEA-S), progesterone, and cortisol were measured at baseline and after 6 and 12 months of treatment. For each hormone, changes from baseline at 6 and 12 months were compared between treatment groups, and differences over time for each group were analyzed. Results Hormonal data were available for 139 postmenopausal patients with a median age of 62 years, with 43 patients assigned to tamoxifen and 96 patients assigned to letrozole alone or combined with zoledronic acid. Baseline values were similar between the two groups for all hormones. Many significant changes were observed between drugs and for each drug over time. Namely, three hormones seemed significantly affected by one drug only: estradiol that decreased and progesterone that increased with letrozole and cortisol that increased with tamoxifen. Both drugs affected FSH (decreasing with tamoxifen and slightly increasing with letrozole), LH (decreasing more with tamoxifen than with letrozole), testosterone (slightly increasing with letrozole but not enough to differ from tamoxifen), and DHEA-S (increasing with both drugs but not differently between them). Zoledronic acid did not have significant impact on hormonal levels. CONCLUSION Adjuvant letrozole and tamoxifen result in significantly distinct endocrine effects. Such differences can explain the higher efficacy of letrozole as compared with tamoxifen.

Compliance and toxicity of adjuvant CMF in elderly breast cancer patients: a single-center experience

BackgroundFew data are available on compliance and safety of adjuvant chemotherapy when indicated in elderly breast cancer patients; CMF (cyclophosphamide, methotrexate, fluorouracil) can be reasonably considered the most widely accepted standard of treatment.MethodsWe retrospectively reviewed compliance and safety of adjuvant CMF in patients older than 60. The treatment was indicated if patients had no severe comorbidity, a high-risk of recurrence, and were younger than 75. Toxicity was coded by NCI-CTC. Toxicity and compliance were compared between two age subgroups (<65, ≥ 65) by Fisher exact test and exact Wilcoxon rank-sum test.ResultsFrom March 1991 to March 2002, 180 patients were identified, 100 older than 60 and younger than 65, and 80 aged 65 or older. Febrile neutropenia was more frequent among older patients (p = 0.05). Leukopenia, neutropenia, nausea, cardiac toxicity and thrombophlebitis tended to be more frequent or severe among elderlies, while mucositis tended to be more evident among younger patients, all not significantly. Almost one half (47%) of the older patients receiving concomitant radiotherapy experienced grade 3–4 haematological toxicity. Compliance was similar in the two groups, with 6 cycles administered in 86% and 79%, day-8 chemotherapy omitted at least once in 36% and 39%, dose reduction in 27% and 38%, prolonged treatment duration (≥ 29 weeks) in 10% and 11% and need of G-CSF in 9% and 18%, among younger and older patients, respectively.ConclusionOur data show that, in a highly selected population of patients 65 or more years old, CMF is as feasible as in patients older than 60 and younger than 65, but with a relevant burden of toxicity. We suggest that prospective trials in elderly patients testing less toxic treatment schemes are mandatory before indicating adjuvant chemotherapy to all elderly patients with significant risk of breast cancer recurrence.

Endocrine Effects of Adjuvant Letrozole + Triptorelin Compared With Tamoxifen + Triptorelin in Premenopausal Patients With Early Breast Cancer

PURPOSE To compare the endocrine effects of 6 months of adjuvant treatment with letrozole + triptorelin or tamoxifen + triptorelin in premenopausal patients with early breast cancer within an ongoing phase 3 trial (Hormonal Adjuvant Treatment Bone Effects study). PATIENTS AND METHODS Prospectively collected hormonal data were available for 81 premenopausal women, of whom 30 were assigned to receive tamoxifen + triptorelin and 51 were assigned letrozole + triptorelin +/- zoledronate. Serum 17-beta-estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), Delta4-androstenedione, testosterone, dehydroepiandrosterone-sulfate, progesterone, adrenocorticotropic hormone (ACTH), and cortisol were measured at baseline and after 6 months of treatment. For each hormone, 6-month values were compared between treatment groups by the Wilcoxon-Mann-Whitney exact test. RESULTS Median age was 44 years for both groups of patients. Letrozole + triptorelin (+/- zoledronate) induced a stronger suppression of median E2 serum levels (P = .0008), LH levels (P = .0005), and cortisol serum levels (P < .0001) compared with tamoxifen + triptorelin. Median FSH serum levels were suppressed in both groups, but such suppression was lower among patients receiving letrozole, who showed significantly higher median FSH serum levels (P < .0001). No significant differences were observed for testosterone, progesterone, ACTH, androstenedione, and dehydroepiandrosterone between the two groups of patients. CONCLUSION Letrozole in combination with triptorelin induces a more intense estrogen suppression than tamoxifen + triptorelin in premenopausal patients with early breast cancer.

Imatinib treatment inhibit IL‐6, IL‐8, NF‐KB and AP‐1 production and modulate intracellular calcium in CML patients

Imatinib (IM) is considered the gold standard for chronic myeloid leukemia (CML) treatment, although resistance is emerging as a significant problem. The proinflammatory cytokines interleukin‐6 (IL‐6) and interleukin‐8 (IL‐8) play an important role in cell proliferation, survival, and resistance to glucocorticoid‐mediated cell death. Several transcription factors such as NF‐KB and AP‐1 are activated in response to physiopathological increases and modulation of intracellular calcium levels. Our previous study demonstrated that lymphocytes from CML patients showed dysregulated calcium homeostasis and oxidative stress. Alteration in ionized calcium concentration in the cytosol has been implicated in the initiation of secretion, contraction, and cell proliferation. In this study, we hypothesized that IL‐6, IL‐8, NF‐kB, AP‐1, and intracellular calcium may be used as selective and prognostic factors to address the follow‐up in CML patients treated with imatinib. Our results demonstrated a significant down‐regulation in IL‐6 and IL‐8 release as well as NF‐kB and AP‐1 activation in lymphomonocytes from Imatinib‐treated patients, compared to samples from untreated patients. In parallel, IM treatment, in vivo and in vitro, were able to modulate the intracellular calcium concentration of peripheral blood mononuclear cells of CML patients by acting at the level of InsP3 receptor in the endoplasmic reticulum and at the level of the purinergic receptors on plasma membrane. The results of this study show that measurements of NF‐kB, AP‐1, IL‐6, IL‐8, and intracellular calcium in CML patients treated with Imatinib may give important information to the hematologist on diagnostic criteria and are highly predictive in patients with newly diagnosed CML. J. Cell. Physiol. 227: 2798–2803, 2012.

The antiestrogen ICI 182,780 inhibits proliferation of human breast cancer cells by interfering with multiple, sequential estrogen-regulated processes required for cell cycle completion.

Antiestrogens are widely used for breast cancer treatment, where they act primarily by inhibiting the mitogenic action of estrogens on tumor cells. The effects of the pure antiestrogen ICI 182,780 on estrogen-regulated cell cycle phase-specific events were investigated here in synchronously cycling human breast cancer (HBC) cells. In early G(1)-arrested MCF-7 or ZR-75.1 cells, 17beta-estradiol (E2) induces rapid activation of the cyclin/Cdk/pRb pathway, as demonstrated by D-type G(1) cyclins accumulation during the first few hours of hormonal stimulation, followed by sequential accumulation of E, A and B1 cyclins and progressive pRb phosphorylation, as cells progress through the cell cycle. When added to quiescent cells together with E2, ICI 182,780 prevents all of the above hormonal effects. Interestingly, in mid-G(1) cells (2-8 h into estrogen stimulation) the antiestrogen causes rapid reversal of hormone-induced D-type cyclins accumulation and pRb phosphorylation, and still fully inhibits G(1)-S transition rate, while in late-G(1) cells it does not prevent S phase entry but still inhibits significantly DNA synthesis rate, S-phase cyclins accumulation and pRb hyperphosphorylation. These results indicate that pure antiestrogens prevent multiple estrogen-induced cell cycle-regulatory events, each timed to allow efficient G(1) completion, G(1)-S transition, DNA synthesis and cell cycle completion.

Dysregulated calcium homeostasis and oxidative stress in chronic myeloid leukemia (CML) cells

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder caused by the oncogenic activity of the Bcr‐Abl protein, a deregulated tyrosine kinase. Calcium may act directly on cellular enzymes and in conjunction with other cellular metabolites, such as cyclic nucleotides, to regulate cell functions. Alteration in the ionized calcium concentration in the cytosol has been implicated in the initiation of secretion, contraction, and cell proliferation as well as the production of reactive oxygen species (ROS) has been correlates with normal cell proliferation through activation of growth‐related signaling pathways. In this study we evaluated in peripheral blood leukocytes from CML patients the role of the balance between intracellular calcium and oxidative stress in CML disease in order to identify possible therapeutic targets in patients affected by this pathology. Our results demonstrated that peripheral blood mononuclear cells derived from CML patients displayed decreased intracellular calcium [Ca2+]i fluxes both after InsP3 as well as ATP and ionomycin (IONO) administration. CML cells showed lower levels of superoxide dismutase (SOD) activity and significantly higher malondialdehyde levels (MDA) than peripheral blood mononuclear cells derived from control patients. Finally we showed that resveratrol is able to down‐regulate InsP3 and ATP effects on intracellular calcium [Ca2+]i fluxes as well as the effects of ATP and IONO on oxidative stress in CML cells. J. Cell. Physiol. 224: 443–453, 2010.

Is epirubicin effective in first-line chemotherapy of metastatic breast cancer (MBC) after an epirubicin-containing adjuvant treatment? A single centre phase III trial.

The aim of the study was to demonstrate the superiority of docetaxel and epirubicin vs docetaxel alone as first-line therapy in metastatic breast cancer patients pretreated with adjuvant or neoadjuvant epirubicin. We compared single agent docetaxel 100 mg m−2 (D) with the combination of docetaxel 80 mg m−2 and epirubicin 75 mg m−2 (ED). The response rate (72 vs 79%), the progression-free survival (median 9 vs 11 months) and the overall survival (median 18 vs 21 months) were not significantly different between the ED (n=26) and D arms (n=25), respectively. Leucopaenia, nausea and stomatitis were significantly worse with ED. In conclusion, epirubicin should not be administered in combination with taxanes in metastatic breast cancer patients relapsed after an anthracycline-based adjuvant or neoadjuvant therapy.