Biomedical subjects

P L Lollini

Publications and source records attributed to P L Lollini.

At least 19 recordsLinked to original sources

PubMed2002

Enhanced inhibition of tumour growth and metastasis, and induction of antitumour immunity by IL-2-IgG2b fusion protein.

Cytokine-immunoglobulin (Ig)-fusion proteins have attracted increasing interest as antitumour agents. Here, we have investigated the antimetastatic and antitumour responses elicited in vivo by mammary adenocarcinoma cells (TS/A) engineered to secrete interleukin (IL)-2-IgG fusion proteins. TS/A cells were transfected with DNA coding for IL-2-IgG2b, IgG2b or IL-2, and injected subcutaneously into syngeneic mice. Animals injected with TS/A-IL-2 or TS/A-IL-2-IgG2b both efficiently rejected tumours, whereas treatment with parental cells or TS/A-IgG2b was lethal. Interestingly, only mice vaccinated with IL-2-IgG2b fusion protein-secreting cells showed a long-lasting protective immunity against a later challenge with parental tumour cells. Moreover, the metastatic potential of TS/A-IL-2-IgG2b-transfected cells was dramatically decreased compared with TS/A-IL-2-cells, with a virtual absence of lung metastases after intravenous injection. Adenocarcinomas secreting IL-2-IgG2b exhibited a more prominent, early and persistent infiltration of CD4+, CD8+ and natural killer (NK) cells than TS/A-IL-2 cells. Therefore, upon transfection into adenocarcinoma cells, the IgG2b part of IL-2 fusion protein exerts intriguing added antitumour properties over IL-2 alone, thus contributing to a long-lasting tumour immunity, probably by the recruitment of specific immune effector cells. These findings suggest a promising new oncotherapeutic strategy for poorly immunogenic tumours: vaccination with tumour cells engineered to secrete IL-2-IgG2b fusion protein.

Adenocarcinoma↗

PubMed2001

Combined allogeneic tumor cell vaccination and systemic interleukin 12 prevents mammary carcinogenesis in HER-2/neu transgenic mice.

Transgenic Balb/c mice expressing the transforming rat HER-2/neu oncogene develop early and multifocal mammary carcinomas. Within the first 5 months of life the tissue-specific expression of HER-2/neu causes a progression in all their 10 mammary glands from atypical hyperplasia to invasive carcinoma. It was previously observed that chronic administration of interleukin (IL)-12 increased tumor latency, but every mouse eventually succumbed to multiple carcinomas. A significant improvement in tumor prevention was sought by administering allogeneic mammary carcinoma cells expressing HER-2/neu combined with systemic IL-12. This treatment reduced tumor incidence by 90% and more than doubled mouse lifetime. For the maximum prevention p185(neu) antigen must be expressed by allogeneic cells. IL-12 treatment strongly increased the cell vaccine efficacy. The mammary glands of mice receiving the combined treatment displayed a markedly reduced epithelial cell proliferation, angiogenesis, and HER-2/neu expression, while the few hyperplastic foci were heavily infiltrated by granulocytes, macrophages, and CD8(+) lymphocytes. Specific anti-HER-2/neu antibodies were produced and a nonpolarized activation of CD4(+) and CD8(+) cells secreting IL-4 and interferon (IFN)-gamma were evident. A central role for IFN-gamma in the preventive effect was proven by the lack of efficacy of vaccination in IFN-gamma gene knockout HER-2/neu transgenic Balb/c mice. A possible requirement for IFN-gamma is related to its effect on antibody production, in particular on IgG2a and IgG2b subclasses, that were not induced in IFN-gamma knockout HER-2/neu mice. In conclusion, our data show that an allogeneic HER-2/neu-expressing cell vaccine combined with IL-12 systemic treatment can prevent the onset of genetically determined tumors.

Adjuvants, Immunologic↗

PubMed2001

Identification of new genes related to the myogenic differentiation arrest of human rhabdomyosarcoma cells.

Rhabdomyosarcoma is a soft tissue tumor committed to the myogenic lineage but arrested prior to terminal differentiation. To identify new genes implicated in the block in myogenic differentiation of rhabdomyosarcoma cells and those responsible for their proceeding along the myogenic pathway we used cDNA microarrays to compare gene expression profiles of two clones of the human embryonal rhabdomyosarcoma cell line RD with different myogenic potentials: RD/12, which is unable to differentiate, and RD/18, which shows elements able to terminally differentiate, as defined by the expression of myosin heavy chain (up to 50% of the population) and the formation of multinucleated myotube-like structures. We identified 80 genes differentially expressed by the two clones. Differentiating RD/18 cells overexpressed the myogenic transcription factor myogenin along with known myogenic markers; myogenin transfection into undifferentiated RD/12 cells was able to revert the phenotype giving rise to 94% of clones displaying a differentiated morphology. RD/18 cells also expressed several genes not known to be expressed in rhabdomyosarcoma or muscle cells, such as pigment-epithelium derived factor and endothelin-3. Poorly differentiated RD/12 cells, along with genes related to mesenchymal lineage or early myogenic commitment, also expressed genes not previously known to be related to the differentiation block of human rhabdomyosarcoma, such as monocyte chemotactic protein-1, connective tissue growth factor and insulin-like growth factor binding protein-5. Differential expression of these genes in a time course of differentiation suggested their potential roles as either new myogenic markers or repressors of differentiation. These results identify a cluster of new genes related to the aberrant myogenic differentiation program of human rhabdomyosarcoma cells.

Cell Differentiation↗

PubMed2001

A light, nontoxic interleukin 12 protocol inhibits HER-2/neu mammary carcinogenesis in BALB/c transgenic mice with established hyperplasia.

With a slight asynchronous but consistent progression, all of the mammary glands of female BALB/c mice transgenic for the transforming rat HER-2/neu oncogene progress to atypical hyperplasia and to invasive carcinoma. Previous studies have shown that chronic administration of interleukin (IL) 12 started at the 2nd week of age hampers this progression because of its ability to inhibit tumor angiogenesis and activate a nonspecific immune response. Here we show that a similar inhibition is achieved when 7-week-old mice with fully blown atypical hyperplasia receive a weekly injection of 100 ng IL-12 for 16 times. This lower-dose and later IL-12 administration induces high and sustained levels of serum IFN-gamma equivalent to those elicited by more frequent administrations. A lower-dose and less toxic treatment may thus be envisaged as a possible option in the management of preneoplastic mammary lesions.

Animals↗

PubMed2001

An anti-apoptotic role for NGF receptors in human rhabdomyosarcoma.

The expression and biological function of Nerve Growth Factor (NGF) receptors was studied in a panel of rhabdomyosarcoma cell lines derived from embryonal and alveolar histotype. All the cell lines expressed both the high affinity receptor TrkA and the low affinity receptor p75(NTR). Treatment with exogenous NGF did not considerably alter rhabdomyosarcoma cell growth or differentiation, but significantly inhibited spontaneous apoptosis as well as apoptosis, and induced by serum starvation or apoptosis induced by treatment with cycloheximide (CHX). Rhabdomyosarcoma cell lines expressed NGF and other neurotrophins and trace amounts of NGF protein were found in the supernatants of rhabdomyosarcoma cell cultures. Blocking the putative autocrine loop with an anti-NGF antibody resulted in an increase in apoptosis compared with control cultures. These data suggest that the simultaneous presence of both high and low affinity NGF receptors engaged by endogenous or exogenous NGF might contribute to the escape from apoptosis exhibited by the rhabdomyosarcoma cells.

Apoptosis↗

PubMed2001

Prevention of spontaneous neu-expressing mammary tumor development in mice transgenic for rat proto-neu by DNA vaccination.

The HER-2/neu proto-oncogene is overexpressed in 20-30% of human breast cancers and is associated with high recurrence risk. The oncogenic potential of HER-2/neu, together with its elevated expression in tumors, cell surface localization, and immunogenicity in some patients, make this oncoprotein an ideal target for immunotherapeutic approaches. To test the efficacy of immune-based strategies in eliciting an antitumor response, we used the N#202 transgenic mouse model engineered to overexpress the rat neu proto-oncogene under the control of the mouse mammary tumor virus promoter; females of this line develop spontaneous focal mammary tumors by 6 months of age. Transgenic mice immunized intramuscularly with a HER-2 cDNA ligated into the VR1012 (VICAL) expression vector under the control of the cytomegalovirus promoter developed significantly fewer spontaneous tumors as compared with mice injected with the empty vector (P < 0.0001) or not injected (P = 0.0006). However, this protection was observed only when immunization was started in 3-month-old but not in 6-month-old mice. These data suggest that the xenogeneic HER-2 DNA sequence can break immune tolerance to rat neu in transgenic N#202 mice and induce protective immunity that impairs the neu oncogene-driven progression of mammary carcinogenesis. The preventive effect achieved by our immunological approach appeared not to be based on anti-neu specific B and T cell immune attacks but was more possibly based on different mechanisms including aspecific and inflammatory immunological responses.

Age Factors↗

PubMed2001

Therapy of lung metastases through combined vaccination with carcinoma cells engineered to release IL-13 and IFN-gamma.

TS/A spontaneous mouse mammary adenocarcinoma cells were engineered to release interferon-gamma (IFN-gamma), a Th1 cytokine (TS/A-IFNgamma) and interleukin-13 (IL-13), a Th2 cytokine (TS/A-IL13). Mice bearing lung micrometastases induced by parental TS/A cells received repeated subcutaneous vaccinations with TS/A-IFN-gamma admixed with TS/A-IL13 engineered cells. This combined treatment cured up to 75% of mice, whereas vaccinations with either TS/A-IFNgamma or TS/A-IL13 alone cured only 20-40% of mice. Combined TS/A-IL13 and TS/A-IFNgamma therapeutic vaccinations elicited a reactive infiltrate of CD4+ and CD8+ lymphocytes in lung metastases and an increased production of IFN-gamma in the spleen and lung, suggesting a shift of the immune response toward the Th1 type. The type of infiltrating cells along with the lack of efficacy in T cell-deficient mice point to a major role of T cells. In conclusion, no antagonism but a synergistic and effective definitive cure stems from the combined vaccination with tumor cells engineered to release a Th1 and a Th2 cytokine.

Adenocarcinoma↗

PubMed2001

Inhibition of insulin-like growth factor I receptor increases the antitumor activity of doxorubicin and vincristine against Ewing's sarcoma cells.

Innovative treatment modalities are needed for Ewing's sarcoma (ES), a neoplasm with a disappointingly low survival rate despite the use of aggressive multimodal therapeutic approaches. We and others (D. Yee et al., J. Clin. Investig., 86: 1806-1814, 1990; K. Scotlandi et al., Cancer Res., 56: 4570-4574, 1996) have previously shown the existence and the pathogenetic relevance of an autocrine loop, mediated by the insulin-like growth factor-I receptor (IGF-IR), which is crucial for survival and proliferation of ES cells in vitro. Moreover, we reported that the IGF-IR-blocking monoclonal antibody (MAb), alphaIR3, as well as suramin, a drug that can interfere with growth factor by binding to the receptors, inhibited both the tumorigenic and the metastatic ability of ES cells in athymic mice. In this study, we analyzed whether agents that can block the IGF-IR-mediated loop are of value in association with conventional cytotoxic drugs for the design of more effective therapeutic regimens. Both alphaIR3 MAb and suramin treatment significantly increased the antitumor in vitro effects of doxorubicin and vincristine, two drugs with a leader action on ES. These findings were obtained by both simultaneous and sequential treatments. Analysis of the proliferation rate and of apoptosis revealed that alphaIR3 MAb and suramin significantly enhanced the G(1)-phase rate induced by doxorubicin, without substantially affecting doxorubicin-G(2)-M-blockage of cell cycle, and significantly increased the induction of apoptosis, which confirmed that the specific blockage of IGF-IR deprives ES cells of an important tool for the prevention of drug-induced apoptosis. Moreover, combination treatments of doxorubicin plus alphaIR3 MAb significantly increase the doxorubicin-induced impairment of the ability of ES cells to form colonies in soft agar. In conclusion, we showed that, in ES, the blockage of IGF-IR by a neutralizing MAb or by suramin may greatly potentiate the antitumor activity of conventional chemotherapeutic drugs.

Antibodies, Monoclonal↗

PubMed2001

[Gene therapy of tumors, state of the art and prospects].

Gene therapy entered the clinical arena more than one decade ago. Hundreds of clinical trials were initiated worldwide to investigate many different approaches to oncological problems. Positive results became available only recently, showing that gene therapy is actually capable of curing human neoplasms. This editorial scrutinizes the whole field of gene therapy for cancer, describing advantages and disadvantages of the various approaches, and trying to forecast the main future developments.

Adenoviridae↗

PubMed2000

DNA vaccination against rat her-2/Neu p185 more effectively inhibits carcinogenesis than transplantable carcinomas in transgenic BALB/c mice.

The ability of vaccination with plasmids coding for the extracellular and the transmembrane domain of the product of transforming rat Her-2/neu oncogene (r-p185) to protect against r-p185(+) transplantable carcinoma (TUBO) cells and mammary carcinogenesis was evaluated. In normal BALB/c mice, DNA vaccination elicits anti-r-p185 Ab, but only a marginal CTL reactivity, and protects against a TUBO cell challenge. Massive reactive infiltration is associated with TUBO cell rejection. In BALB/c mice transgenic for the rat Her-2/neu gene (BALB-neuT), DNA vaccination elicits a lower anti-r-p185 Ab response, no CTL activity and only incompletely protects against TUBO cells, but markedly hampers the progression of carcinogenesis. At 33 wk of age, when control BALB-neuT mice display palpable tumors in all mammary glands, about 60% of immunized mice are tumor free, and tumor multiplicity is markedly reduced. Tumor-free mammary glands still display the atypical hyperplasia of the early stages of carcinogenesis, and a marked down-modulation of r-p185, along with a massive reactive infiltrate. However, BALB-neuT mice protected against mammary carcinogenesis fail to efficiently reject a TUBO cell challenge. This suggests that the mechanisms required for the rejection of transplantable tumors may not coincide with those that inhibit the slow progression of carcinogenesis.

Adenocarcinoma↗

PubMed2000

CD99 engagement: an effective therapeutic strategy for Ewing tumors.

CD99 is a Mr 32,000 transmembrane molecule that shows a high level of expression on cells of the hemopoietic system as well as on Ewing tumor cells. Within the hematopoietic system, CD99 has been implicated in cell adhesion and cell death, participating in this way in the differentiation of T-cell precursors. In this study, we demonstrate that engagement of CD99 significantly inhibits the in vitro and in vivo growth ability of Ewing tumor cells by delivering an apoptotic stimulus and reducing the malignant potential of these cells. Moreover, we show that anti-CD99 monoclonal antibodies may be advantageously used in association with conventional anticancer agents. These results provide a novel entry site for therapeutic intervention, which may have application in the care of patients with Ewing tumor, and warrant additional studies to clarify the molecular mechanisms activated by CD99 engagement.

12E7 Antigen↗

PubMed2000

Gene transfer of a secretable form of IL-15 in murine adenocarcinoma cells: effects on tumorigenicity, metastatic potential and immune response.

IL-15 is an immunostimulatory cytokine with IL-2-like activities. To exploit the potential role of IL-15 in cancer immuno-/gene therapy, we engineered murine TS/A cells with different IL-15 cDNA constructs. Significant IL-15 secretion was achieved only by the use of a modified cDNA encoding for an IL-15 pre-protein bearing the IgK light chain signal peptide. Different TS/A clones (TS/A IL-15 C6, C23, C29) producing 390 to 1,600 pg/ml biologically active IL-15 showed reduced tumorigenicity when implanted s.c. in syngeneic mice and significantly reduced metastatic potential by i.v. injection. Tumorigenicity of s.c. TS/A IL-15 was restored in animals depleted of CD8(+) lymphocytes or of natural killer cells and partially in CD4(+)-depleted mice. TS/A IL-15 cells displayed a significantly reduced growth rate by s.c. implant in nude mice. Also, >50% syngeneic animals rejecting TS/A IL-15 were resistant to a subsequent rechallenge with wild-type tumor (TS/Apc), indicating induction of protective immunity against TS/A tumor-associated antigens (TAAs). Cytolytic T lymphocyte (CTL) activity, specifically inhibited by anti-CD3 antibodies, was inducible in the splenocytes of TS/A IL-15-immunized animals by mixed lymphocyte/tumor culture (MLTC), and IFN-gamma was released in the supernatant of MLTC, mainly by CD8(+) cells. Immunohistochemistry of the TS/A IL-15 tumor area revealed the presence of an inflammatory infiltrate with predominant natural killer, macrophage, and granulocyte components and expression of IFN-gamma as a distinctive secondary cytokine. Use of TS/A IL-15 mitomycin-treated cells for therapeutic vaccination in experimental TS/A metastasis was effective in 60% of animals treated; these animals showed no metastatic tumor growth.

Adenocarcinoma↗

PubMed2000

p185(neu) protein is required for tumor and anchorage-independent growth, not for cell proliferation of transgenic mammary carcinoma.

Transgenic FVB-NeuN mice (N202) bearing the rat neu protooncogene driven by the mouse mammary tumor virus promoter/enhancer develop focal mammary carcinomas overexpressing the neu-encoded p185(neu) protein. In vitro expression of p185(neu) among mammary carcinoma cultures was heterogeneous, and we could establish some cell lines and clones displaying a complete loss of p185(neu) expression, along with others with very high p185(neu) protein level. Upon in vivo injection, p185(neu)-positive cells gave rise to fast-growing tumors with a short latency, while p185(neu)-negative cells required a very long latency time, and the resulting tumors were invariably p185(neu)-positive. The lower growth ability of p185(neu)-negative cells in vivo was also confirmed in athymic nude mice. In vitro, analysis of anchorage-independent growth in soft agar revealed colony formation from p185(neu)-positive but not p185(neu)-negative cells. The direct involvement of p185(neu) in clonogenicity was demonstrated by the inhibition of p185(neu)-positive colony growth in soft agar in the presence of an anti-p185(neu) monoclonal antibody. By contrast, a higher level of anchorage-dependent clonogenic growth and proliferation was observed in p185(neu)-negative cells as compared to p185(neu)-positive cells, thus explaining the relative ease with which p185(neu)-negative cell lines and clones were established in vitro. Together, the results indicate that p185(neu) expression can lead to tumor formation and metastasis through the modification of intrinsic properties of cells related to anchorage-independent growth ability rather than to proliferation or host-dependent mechanisms.

Animals↗

PubMed2000

Expression of HER/erbB family of receptor tyrosine kinases and induction of differentiation by glial growth factor 2 in human rhabdomyosarcoma cells.

Five human rhabdomyosarcoma cell lines were used to investigate the surface expression of HER/erbB receptors, particularly of HER-2, HER-3 and HER-4, by flow cytometry. HER-2 was expressed in 3/5 rhabdomyosarcoma cell lines. HER-3 was expressed in all rhabdomyosarcoma cell lines. None of the rhabdomyosarcoma cell lines investigated showed HER-4 surface expression. To study the biological activity of HER/erbB receptors in rhabdomyosarcomas, cells were cultured in the presence of glial growth factor 2 (GGF-2), a specific ligand of HER-3 that is able to stimulate myogenesis in normal myoblasts. In 3 of 3 human rhabdomyosarcoma cell lines positive for both HER-2 and HER-3 receptors, the treatment with GGF-2 induced a significant increase in myogenic differentiation.

Cell Differentiation↗

PubMed2000

Immunoprevention of cancer: is the time ripe?

Immunotherapy applied to patients with established tumors rarely leads to an objective response, whereas patients apparently free from disease after conventional treatment and at risk of recurrence are beginning to receive vaccination. New classes of patients or not-yet patients are those with a high genetic or environmental risk of developing cancer. They may draw benefit from a "soft" treatment such as vaccination. This overview discusses the prospects of immune stimulation as a means of cancer prevention by inducing various forms of nonspecific or even specific immunity. Attainment of this goal provides the rationale and motivation for embarking on such a new and potentially rewarding enterprise.

Humans↗

PubMed2000

Tumor rejection and immune memory elicited by locally released LEC chemokine are associated with an impressive recruitment of APCs, lymphocytes, and granulocytes.

The human beta chemokine known as LEC (also called NCC-4, HCC-4, or LMC) displays chemotactic activity for monocytes and dendritic cells. The possibility that its local presence increases tumor immunogenicity is addressed in this paper. TSA parental cells (TSA-pc) are poorly immunogenic adenocarcinoma cells that grow progressively, kill both nu/nu and syngeneic BALB/c mice, and give rise to lung metastases. TSA cells engineered to release LEC (TSA-LEC) are still able to grow in nu/nu mice, but are promptly rejected and display a marginal metastatic phenotype in BALB/c mice. Rejection is associated with a marked T lymphocyte and granulocyte infiltration, along with extensive macrophage and dendritic cell recruitment. NK cells and CD4+ T lymphocytes are uninfluential in TSA-LEC cell rejection, whereas both CD8+ lymphocytes and polymorphonuclear leukocytes play a major role. An antitumor immune memory is established very quickly after rejection, since 6 days later 75% of BALB/c mice were already resistant to a TSA-pc challenge. Spleen cells from rejecting mice display specific cytotoxic activity against TSA-pc and secrete IFN-gamma and IL-2 when restimulated by TSA-pc. The ability of LEC to markedly improve recognition of poorly immunogenic cells by promoting APC-T cell cross-talk suggests that it could be an effective component of antitumor vaccines.

Adenocarcinoma↗

PubMed2000

Tamoxifen chemoprevention of a hormone-independent tumor in the proto-neu transgenic mice model.

We evaluated the effect of tamoxifen (TAM) on tumor development in proto-neu transgenic mice that spontaneously develop mammary carcinomas overexpressing the neu protein. These mammary carcinomas are hormone independent because superimposable growth of transplants was observed in females and males. Virgin transgenic mice treated with TAM from 24 weeks of age, ie., when subclinical mammary tumors are already present, showed a slightly accelerated tumor development. In contrast, transgenic mice treated with TAM starting at 12 weeks of age, when subclinical tumors are not yet present, showed a 50% reduction of tumor incidence. Light microscopy analysis of the mammary gland of these mice revealed an apparently normal ductal branching but a complete regression of the acini. In conclusion, TAM can prevent the occurrence of hormone-independent breast carcinoma if given early enough to inhibit normal cells.

Animals↗

PubMed2000

Ability of systemic interleukin-12 to hamper progressive stages of mammary carcinogenesis in HER2/neu transgenic mice.

Previous studies in mice have shown that chronic administration of recombinant interleukin-12 (IL-12) hampers the progression of both chemical- and oncogene-dependent carcinogenesis. This suggests that a new preventive strategy may be envisaged for individuals with a genetic risk of cancer or carrying preneoplastic lesions. Starting at progressive stages of mammary carcinogenesis, female BALB/c and FVB mice carrying the activated rat HER2/neu oncogene (BALB-neuT) or the proto-oncogene (FVB-neuN) under the mouse mammary tumor virus promoter received multiple 5-day courses of different doses of IL-12. The times of tumor appearance, multiplicity, and histopathological features of the neoplastic lesions were evaluated. In both BALB-neuT and FVB-neuN mice, 5-day i.p. courses of 50/100 ng of IL-12/day inhibited mammary carcinogenesis when they coincided with the progression of early preneoplastic lesions. Inhibition appears to depend primarily on the ability of IL-12 to interfere with early tumor angiogenesis. Later treatments are much less effective, and daily doses of 10 and 2 ng are useless. The efficacy of early IL-12 courses suggests that they could be used to prevent mammary tumors in individuals at risk, whereas their lower efficacy in later stages of carcinogenesis and the dose range required pose some constraints on their use in the management of overt preneoplastic lesions. Precise understanding of tumor progression means that effective treatments can be commenced relatively late in the life of individuals at risk and that no lifetime administration is required.

Animals↗