Guido Forni

A novel transforming protein (SHC) with an SH2 domain is implicated in mitogenic signal transduction.

A new SH2-containing sequence, SHC, was isolated by screening cDNA libraries with SH2 representative DNA probes. The SHC cDNA is predicted to encode overlapping proteins of 46.8 and 51.7 kd that contain a single C-terminal SH2 domain, and an adjacent glycine/proline-rich motif with regions of homology with the alpha 1 chain of collagen, but no identifiable catalytic domain. Anti-SHC antibodies recognized three proteins of 46, 52, and 66 kd in a wide range of mammalian cell lines. These SHC proteins complexed with and were phosphorylated by activated epidermal growth factor receptor. The physical association of SHC proteins with activated receptors was recreated in vitro by using a bacterially expressed SHC SH2 domain. NIH 3T3 mouse fibroblasts that constitutively overexpressed SHC acquired a transformed phenotype in culture and formed tumors in nude mice. These results suggest that the SHC gene products couple activated growth factor receptors to a signaling pathway that regulates the proliferation of mammalian cells.

Systemic Spread Is an Early Step in Breast Cancer

It is widely accepted that metastasis is a late event in cancer progression. Here, however, we show that tumor cells can disseminate systemically from earliest epithelial alterations in HER-2 and PyMT transgenic mice and from ductal carcinoma in situ in women. Wild-type mice transplanted with single premalignant HER-2 transgenic glands displayed disseminated tumor cells and micrometastasis in bone marrow and lungs. The number of disseminated cancer cells and their karyotypic abnormalities were similar for small and large tumors in patients and mouse models. When activated by bone marrow transplantation into wild-type recipients, 80 early-disseminated cancer cells sufficed to induce lethal carcinosis. Therefore, release from dormancy of early-disseminated cancer cells may frequently account for metachronous metastasis.

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.

Vaccines for tumour prevention.

Despite tremendous progress in basic and epidemiological research, effective prevention of most types of cancer is still lacking. Vaccine use in cancer therapy remains a promising but difficult prospect. However, new mouse models that recapitulate significant features of human cancer progression show that vaccines can keep precancerous lesions under control and might eventually be the spearhead of effective and reliable ways to prevent cancer.

Phosphoinositide 3-kinase p110beta activity : key role in metabolism and mammary gland cancer but not development

The phosphoinositide 3-kinase p110β subunit has noncatalytic functions; its catalytic activity is pertinent to both diabetes and cancer. Unveiling p110β Phosphatidylinositide 3-kinase (PI3K) signaling has been implicated in the response to insulin and various growth factors. However, the specific role of the β isoform of the PI3K catalytic subunit (p110β) has been unclear. Analysis of mouse mutants carrying a catalytically inactive form of p110β reveals that it possesses noncatalytic as well as catalytic functions. Moreover, its catalytic activity is involved in sustaining the response to insulin signaling and in mediating forms of breast cancer associated with oncogenic epidermal growth factor signaling. The phosphoinositide 3-kinase (PI3K) pathway crucially controls metabolism and cell growth. Although different PI3K catalytic subunits are known to play distinct roles, the specific in vivo function of p110β (the product of the PIK3CB gene) is not clear. Here, we show that mouse mutants expressing a catalytically inactive PIK3CBK805R mutant survived to adulthood but showed growth retardation and developed mild insulin resistance with age. Pharmacological and genetic analyses of p110β function revealed that p110β catalytic activity is required for PI3K signaling downstream of heterotrimeric guanine nucleotide–binding protein (G protein)–coupled receptors as well as to sustain long-term insulin signaling. In addition, PIK3CBK805R mice were protected in a model of ERBB2-driven tumor development. These findings indicate an unexpected role for p110β catalytic activity in diabetes and cancer, opening potential avenues for therapeutic intervention.

2011: the immune hallmarks of cancer

Ten years after the publication of the position paper “The hallmarks of cancer” (Hanahan and Weinberg Cell 100:57–70, 2000), it has become increasingly clear that mutated cells on their way to giving rise to a tumor have also to learn how to thrive in a chronically inflamed microenvironment, evade immune recognition, and suppress immune reactivity. Genetic and molecular definition of these three immune hallmarks of cancer offers the opportunity to learn how to deploy specific countermeasures to reverse the situation in favor of the immune system and, eventually, the patient. This new information could be channeled to address what seem to be the three major hallmarks for the immune control of cancer progression: effective procedures to activate immune reactivity; characterization of not-disposable oncoantigens; and counteraction of immune suppression.

Cytokines, tumour-cell death and immunogenicity: a question of choice.

Abstract How do cytokines released by engineered tumour cells provoke tumour rejection and an immune memory? Is vaccination with tumour cells that have been engineered to secrete cytokines a viable therapeutic perspective? Piero Musiani and colleagues have sought an answer to these questions by transfecting the same tumour with the genes of various cytokines and elucidating the features of the reactions elicited.

Treatment of recurrent squamous cell carcinoma of the head and neck with low doses of lnterleukin‐2 injected periiymphatically

Ten patients with recurrent squamous cell carcinoma of the head and neck received daily injections of interleukin‐2 (IL‐2) from the Jurkat T‐cell line purified by high pressure liquid chromatography for 10 days. Two hundred units of IL‐2 in 0.5 ml were injected 1.5 cm from the insertion of the sternocleidomastoid muscle on the mastoid. When possible, courses were repeated at 45‐day intervals. IL‐2 was ineffective in two patients who had already undergone functional or radical neck dissection. By contrast, in six patients with contralateral or bilateral cervical lymph nodes, complete or partial disappearance of the tumor was observed. The injections were occasionally followed by moderate local swelling and lymph node pain, but no systemic disturbances.

Electroporated DNA Vaccine Clears Away Multifocal Mammary Carcinomas in Her-2/neu Transgenic Mice

The transforming rat Her-2/neu oncogene embedded into the genome of virgin transgenic BALB/c mice (BALB-neuT) provokes the development of an invasive carcinoma in each of their 10 mammary glands. i.m. vaccination with DNA plasmids coding for the extracellular and transmembrane domains of the protein product of the Her-2/neu oncogene started when mice already display multifocal in situ carcinomas temporarily halts neoplastic progression, but all mice develop a tumor by week 43. By contrast, progressive clearance of neoplastic lesions and complete protection of all 1-year-old mice are achieved when the same plasmids are electroporated at 10-week intervals. Pathological findings, in vitro tests, and the results from the immunization of both IFN-gamma and immunoglobulin gene knockout BALB-neuT mice, and of adoptive transfer experiments, all suggest that tumor clearance rests on the combination of antibodies and IFN-gamma-releasing T cells. These findings show that an appropriate vaccine effectively inhibits the progression of multifocal preneoplastic lesions.

Zoledronic acid repolarizes tumour-associated macrophages and inhibits mammary carcinogenesis by targeting the mevalonate pathway

It is unknown whether zoledronic acid (ZA) at clinically relevant doses is active against tumours not located in bone. Mice transgenic for the activated ErbB‐2 oncogene were treated with a cumulative number of doses equivalent to that recommended in human beings. A significant increase in tumour‐free and overall survival was observed in mice treated with ZA. At clinically compatible concentrations, ZA modulated the mevalonate pathway and affected protein prenylation in both tumour cells and macrophages. A marked reduction in the number of tumour‐associated macrophages was paralleled by a significant decrease in tumour vascularization. The local production of vascular endothelial growth factor and interleukin‐10 was drastically down‐regulated in favour of interferon‐γ production. Peritoneal macrophages and tumour‐associated macrophages of ZA‐treated mice recovered a full M1 antitumoral phenotype, as shown by nuclear translocation of nuclear factor kB, inducible nitric oxide synthase expression and nitric oxide production. These data indicate that clinically achievable doses of ZA inhibit spontaneous mammary cancerogenesis by targeting the local microenvironment, as shown by a decreased tumour vascularization, a reduced number of tumour‐associated macrophages and their reverted polarization from M2 to M1 phenotype.