Paola Faraoni

Bcl-w expression in colorectal adenocarcinoma.

We have found that the anti-apoptotic Bcl-2 family protein, Bcl-w, was frequently expressed in colorectal adenocarcinomas, with 69/75 showing positive staining with anti-Bcl-w IgG. Adenomas demonstrated a much lower frequency of Bcl-w expression (only 1 of 17), as did adenocarcinomas from other epithelial tissues such as breast (0/8), stomach (1/12) and cervix (0/12). Bcl-w status could be related to the histopathological classification of the tumours, with TNM stage III tumours showing significantly higher levels of expression than tumours of better prognostic grade (at P = 0.009). Those patients with node involvement also had tumours with significantly elevated levels of Bcl-w (at P = 0.02), compared to those which were node-negative. The results suggest that Bcl-w could play a general role in the progression from adenoma to adenocarcinoma in the colorectal epithelium. Currently, more data are being collected to allow us to assess the importance of Bcl-w for disease progression and patient survival.

Carborane derivatives loaded into liposomes as efficient delivery systems for boron neutron capture therapy.

Boron neutron capture therapy (BNCT) is an anticancer therapy based on the incorporation of (10)B in tumors, followed by neutron irradiation. Recently, the synthesis and delivery of new boronated compounds have been recognized as some of the main challenges in BNCT application. Here, we report on the use of liposomes as carriers for BNCT active compounds. Two carborane derivatives, i.e., o-closocarboranyl beta-lactoside (LCOB) and 1-methyl-o-closocarboranyl-2-hexylthioporphyrazine (H(2)PzCOB), were loaded into liposomes bearing different surface charges. The efficacy of these formulations was tested on model cell cultures, that is, DHD/K12/TRb rat colon carcinoma and B16-F10 murine melanoma. These induce liver and lung metastases, respectively, and are used to study the uptake of standard BNCT drugs, including borophenylalanine (BPA). Boron concentration in treated cells was measured by alpha spectrometry at the TRIGA mark II reactor (University of Pavia). Results showed high performance of the proposed formulations. In particular, the use of cationic liposomes increased the cellular concentration of (10)B by at least 30 times more than that achieved by BPA.

In vivo effects of rosiglitazone in a human neuroblastoma xenograft

Background:Neuroblastoma (NB) is the most common extra-cranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. There is in vitro evidence that the peroxisome proliferator-activated receptor γ (PPARγ) might be a target for pharmacological intervention in NB. We have previously demonstrated that the PPARγ agonist rosiglitazone (RGZ) exerts strong anti-tumoural effects in the human NB cell line, SK-N-AS. The aim of this study was to evaluate whether RGZ maintains its anti-tumoural effects against SK-N-AS NB cells in vivo.Methods and results:For this purpose, tumour cells were subcutaneously implanted in nude mice, and RGZ (150 mg kg−1) was administered by gavage daily for 4 weeks. At the end of treatment, a significant tumour weight inhibition (70%) was observed in RGZ-treated mice compared with control mice. The inhibition of tumour growth was supported by a strong anti-angiogenic activity, as assessed by CD-31 immunostaining in tumour samples. The number of apoptotic cells, as determined by cleaved caspase-3 immunostaining, seemed lower in RGZ-treated animals at the end of the treatment period than in control mice, likely because of the large tumour size observed in the latter group.Conclusions:To our knowledge, this is the first demonstration that RGZ effectively inhibits tumour growth in a human NB xenograft and our results suggest that PPARγ agonists may have a role in anti-tumoural strategies against NB.

Correlation between DNA content and p53 deletion in colorectal cancer.

OBJECTIVE To find out whether tumour DNA content correlates with allelic loss of p53 and other pathological features in primary colorectal carcinomas. DESIGN Ongoing prospective study. SETTING University hospital, Italy. SUBJECTS 128 patients who had undergone radical resections for colorectal carcinoma. INTERVENTIONS Flow cytometric measurement of tumour DNA content and detection of allelic loss on the short arm of chromosome 17 by Southern blot (restriction fragment length polymorphism) analysis in fresh tumour specimens. MAIN OUTCOME MEASURES Correlation between DNA ploidy and deletion of p53, as well as between these two genetic events and clinicopathological variables. RESULTS Interpretable DNA histograms were obtained for 122 tumour specimens. Forty-three tumours (35%) were diploid and 79 (65%) aneuploid. The diploid tumours were significantly more common in the proximal colon (from the caecum to the splenic flexure) than in the distal colon (from the descending colon to the rectum) (p = 0.002). The allelic state on the short arm of chromosome 17 was evaluated in 80 heterozygous patients. Forty-four tumour specimens (55%) showed deletion of 17p. Allelic loss of p53 was significantly more common in the distal and rectal tumours than in the proximal ones (p < 0.0001). Aneuploidy was more common among those tumours which had shown deletion of p53 than in those that had not (p = 0.0008). CONCLUSIONS DNA aneuploidy was significantly associated with the deletion of the p53 gene. This suggests that the functional loss of p53 may favour the growth and establishment of an aneuploid cell population within tumours. Tumours of the proximal and distal colon differ in their genetic nature.

3H‐Thymidine labelling index (TLI) as a marker of tumour growth heterogeneity: evaluation in human solid carcinomas

Many studies deal with the analysis of cell kinetic, cytogenetic, biochemical and molecular cell biology parameters to identify prognostic factors relating to tumour growth but all methods use only a small part of the total tumour mass. This study is devoted to the analysis of the heterogeneity of the growth of human solid tumours assaying proliferative activity by means of 3H‐thymidine labelling index (TLI) in a fixed number of samples collected in different areas of the lesion (larynx and colon cancers), or in different lesions of the same subject (breast and bladder cancers). Each sample (at the macroscopic level) was divided into small fragments (at the microscopic level) and proliferative activity was determined. The analysis of variance for hierarchical designs demonstrated that in all cases a high component of the variance is attributable to the subjects and to the fragments whereas the variance attributable to the different areas is very low. The heterogeneity of proliferative activity displays a higher focal variability among the fragments (microscopic level) compared with that among areas (macroscopic level) within subjects, provided an adequate number of fragments and cells are counted. In multiple synchronous carcinoma of the bladder the wide variability of proliferation among the single lesions demonstrated that it is necessary to analyse all the tumours in a subject because each one is characterized by a different cell growth potential.

B-cell lymphoma 2 and β-catenin expression in colorectal cancer and their prognostic role following surgery

The prognosis of colorectal cancer depends on the stage of the disease. However, even within the same stage there may be different outcomes in terms of recurrence and survival. Therefore, it is clear that as well as pathological stage, novel biomarkers that are capable of improving risk stratification and therapeutic decision-making are required. The present study aimed to evaluate the potential roles of two previously proposed biomarkers of tumour status: B-cell lymphoma 2 (Bcl-2) and β-catenin. A total of 412 patients undergoing surgery for primary colorectal cancer were studied. Tumour specimens of the patients were collected, fixed and processed for immunohistochemical detection of Bcl-2 and β-catenin. The data were then analyzed in relation to disease-free survival and overall survival. Pathological stage was the only variable that was significantly correlated with both disease-free and overall survival. The expression levels of neither Bcl-2 nor β-catenin were able to accurately predict prognosis. However, there was a clear association between nuclear β-catenin expression levels and disease-free survival in the three tumour stages. There was an increased hazard ratio in stage I and II nuclear β-catenin positive tumours, whereas there was a marked decrease in risk in stage III positive tumours. A similar effect was also observed with regards to overall survival, however this finding was not significant. The results of the present study suggest that conventional pathological tumour staging is the only accurate prognostic method. Neither Bcl-2 or β-catenin were shown to be useful biomarkers for the prognosis of colorectal cancer. However, the heterogeneous behaviour of nuclear β-catenin expression in the various tumour stages may indicate a possible role in predicting the response of patients to chemotherapy. Therefore, nuclear β-catenin expression may be a biomarker for the prediction of improved responses to chemotherapy.

Colonic Cell Proliferation in Normal Mucosa of Patients with Colon Cancer

Cell kinetics parameters have been analysed in colonic mucosa at different distances from a tumour in patients with colon carcinoma. Total cell number (TCN), 3H thymidine labelling index (TLI), mitotic index (MI), Goblet cell index (GCI) and the distribution of labelled cells along the crypt column (cell position frequency plot) were determined in well-aligned crypts. Total cell number, GCI and the labelled cell position frequency plots were similar in different samples from the same individual. A negative linear correlation between TCN and TLI was observed. The analysis of the cell position plots showed two patterns 1) with a high concentration in the bottom fifth of the crypt and 2) with frequent labelled cells at high positions. Whereas a negative correlation between overall TLI and the percent contribution to the TLI of the lowermost fifth was seen, the correlation was positive for the next 3 fifths and labelling was absent in the last part of the crypt.

Side effects of intra-gastric photodynamic therapy: an in vitro study

Since many years it has been acknowledged that some bacterial species, among which H. pylori, P. aeruginosa, P. acnes accumulate endogenous photosensitizers (PS) in the form of porphyrins. This makes antibacterial photodynamic therapy (PDT) easier to perform due to the possible avoidance of external PS. In this study, we focus on gastric infections associated with the presence of Helicobacter pylori (H. pylori), known to accumulate and release both protoporphyrin IX (PPIX) and coproporphyrins. PDT versus H. pylori can be carried out by modified endoscopes or by new ingestible luminous devices under development. In both cases of in vitro and in vivo applications, either for therapy (PDT) or diagnosis, scientific literature lacks studies on the possible side-effects of light treatments on the surrounding tissues. To this aim we evaluated in vitro side-effects due to a possible intrinsic photosensitivity of gastric mucosa or to a photosensitization by the PS released from the bacterium itself. Photo-toxicity studies were conducted on the AGS cell line (ATCC® CRL-1739™), commonly used as a model for the stomach mucosa tissue, considering PPIX as the photosensitizing agent. After first evaluations of PPIX dark toxicity, its uptake and accumulation sites, photo-toxicity tests were conducted using a LED light source peaked at 400 nm, by varying both PPIX concentration (50 nM - 2 μM) and light dose in the range 0.6-13 J/cm2, representing different treatment procedures found in literature. The oxidative stress consequent to irradiation was investigated both in terms of ROS production and assessment of the activity of enzymes involved in ROS-related biological mechanisms. A significant phototoxic effect was found only for PPIX concentration > 100 nM for all tested light doses. This indicates that the evaluated photo-treatments do not cause side effects even with the sensitization due to PPIX released by the bacteria.

EGFR-Targeted Magnetic Nanovectors Recognize, in Vivo, Head and Neck Squamous Cells Carcinoma-Derived Tumors

Head and neck squamous cell carcinomas (HNSCC) are a diverse group of tumors with high morbidity and mortality that have remained mostly unchanged over the past decades. The epidermal growth factor receptor (EGFR) is often overexpressed and activated in these tumors and strongly contributes to their pathogenesis. Still, EGFR-targeted therapies such as monoclonal antibodies and kinase inhibitors have demonstrated only limited improvements in the clinical outcome of this disease. Here, we take advantage of the extraordinary affinity of EGF for its cognate receptor to specifically target magnetite-containing nanoparticles to HNSCC cells and mediate, in vitro, their cellular upload. On the basis of this, we show efficient accumulation, in vivo, of such nanoparticles in subcutaneous xenograft tumor tissues in sufficient amounts to be able to mediate visualization by magnetic resonance imaging. Overall, our EGF-coated nanosystem may warrant, in the near future, novel and very efficient theranostic approaches to HNSCC.