Guido Nicolò

Identification of a Glioblastoma-Associated Tenascin-C Isoform by a High Affinity Recombinant Antibody

Tenascin-C exists in several polymorphic isoforms due to alternative splicing of nine fibronectin-like type III repeats. Large Tenascin-C isoforms are present in almost all normal adult tissues but are upregulated in fetal, regenerating, and neoplastic tissues. Here, we report a human antibody fragment, TN11, derived from a phage library with high affinity for the spliced repeat C and demonstrate that this repeat is undetectable in normal adult tissues, barely detectable or undetectable in breast, lung and gastric carcinomas, meningioma, and low grade astrocytoma, but extremely abundant in high grade astrocytoma (grade III and glioblastoma), especially around vascular structures and proliferating cells. The antibody appears to have potential for development of a therapeutic agent for patients with high grade astrocytoma.

Expression of tenascin and of the ED-B containing oncofetal fibronectin isoform in human cancer

Tenascin (TN) and the oncofetal ED-B containing fibronectin isoform (B-FN) have been reported to be stromal markers of a number of malignancies. Here we report on studies of the distribution of TN and B-FN in normal adult tissues and in benign and malignant tumors, as well as on the levels of the B-FN mRNA in cultured fetal and non-fetal human fibroblasts originating from different tissues. B-FN has an extremely restricted distribution in normal adult tissues, is not expressed in benign tumors, but is greatly expressed in a high percentage of malignant tumors. On the contrary, human TN in normal adult tissues is less restricted than what has previously been reported and it is largely expressed in a number of both benign and malignant tumors. Moreover, we observed a great variability in the relative amount of B-FN mRNA among the 17 normal human fibroblast cell lines tested. We found very low levels in non-fetal skin fibroblasts and higher levels in fetal lung fibroblasts. We also found differences in the relative amounts of B-FN mRNA between fibroblast cell lines originating from the skin and the lung of the same subject.

Analysis of HLA-G expression in breast cancer tissues.

Among the different mechanisms by which cancer can elude the immune system, alterations in the expression of human leukocyte antigen (HLA) class I molecules on tumor cells may play a crucial role by impairing the HLA molecules interaction with T and natural killer (NK) cells specific receptors. More recently, aberrant expression of HLA-G has been described in different tumor tissues in addition to HLA class I downregulation. The HLA-G molecule is a nonclassical HLA class I antigen selectively expressed by trophoblast and thymic epithelial cells. Several studies reported that the HLA-G function might represent an additional mechanism of tumor immune escape, mainly inhibiting NK and cytotoxic T-cell activity. Here we report the analysis of HLA-G expression both at RNA level by reverse transcriptase-polymerase chain reaction and at protein level by Western blot and immunohistochemistry in 25 breast cancer patient tissues. The aim of this study was to elucidate the HLA-G gene expression pattern in breast tumor tissues and correlate it with HLA class I alterations. Our results demonstrated that HLA-G molecules expression was never found even in a group of patients revealing HLA class I total loss, and that HLA-G is not expressed in breast cancer tissue with a low-tumor grade (G1-G2) and minimal stromal contamination.

Antitumoral Activity of Human Fibroblast Interferon Administered Intranodularly

Human fibroblast interferon was given intranodularly to 14 patients with cutaneous metastases from breast cancer and malignant melanoma; 1,000,000 units/cm3 of tumor tissue was administered daily for 8-10 days. 13 patients were evaluated. Complete response was achieved in 1 of 7 breast carcinoma nodules and in 2 of 6 melanoma nodules; partial response was achieved in 1 of 7 breast carcinoma and in 3 of 6 melanoma nodules. The overall objective response was therefore 7 of 13 (53.8%) metastatic nodules. Pathological complete response was confirmed in 2 of 3 complete clinical responses. Necrosis, lymphocytic infiltration and fibrosis were observed in all the specimens pathologically examined. In spite of a clear antitumoral activity, this approach does not appear to have clinical significance due to its extremely localized effect.

Intercellular adhesion molecule-1 (ICAM-1) and granulocyte-macrophage colony stimulating factor (GM-CSF) co-expression in cutaneous malignant melanoma lesions.

The expression of intercellular adhesion molecule-1 (ICAM-1) and granulocyte-macrophage colony stimulating factor (GM-CSF) was investigated in 25 melanoma patients by evaluating 34 fresh biopsy specimens. ICAM-1 in situ hybridization and immunochemistry for ICAM-1 and GM-CSF were performed. Most of the metastatic melanoma samples (12 out of 18) and a few of the primary melanoma lesions (three out of 16) showed ICAM-1 expression. The expression of ICAM-1 was significantly (P < 0.01) higher in metastatic lesions than in primary tumours. GM-CSF mRNA and protein were detected in 10 of the 18 metastatic samples and in two of the 15 primary lesions. A significantly high degree (P < 0.0002) of concordance between ICAM-1 and GM-CSF expression was observed: the samples that were negative or positive for ICAM-1 expression were correspondingly negative or positive for GM-CSF. Correlation with clinical and histological parameters was examined. The expression of both molecules in metastatic samples was found to be significantly (P < 0.001) associated with a shorter recurrence-free period. These findings, if confirmed by a wider number of patients, could suggest the prognostic value of the simultaneous, and probably co-ordinated, expression of ICAM-1 and GM-CSF. They also highlight the importance of preventive molecular and biochemical characterization of neoplastic cell cytokine receptors, specifically focusing on the particular cytokine to be used as anticancer therapy and/or as adjunct to chemotherapy.

Expression and mislocalization of mutant p16 proteins in melanocytic lesions from familial melanoma patients

Little is known about the correlation between the loss of p16 expression and tumor progression in familial melanoma; no systematic study has been conducted on p16 expression in melanocytic tumors from patients carrying germline CDKN2A mutations. We analyzed 98 early primary lesions from familial patients, previously tested for germline CDKN2A status, by quantitative immunohistochemistry using 3 p16 antibodies. We found that p16 expression was inversely correlated with tumor progression and was significantly lower in melanomas, including in situ lesions, than in nevi. Of other features analyzed, tumor thickness showed the most significant correlation with p16 levels. Lesions from mutation-negative patients displayed combined nuclear and cytoplasmic staining. However, some mutation-positive lesions (ie, G101W, 113insR, M53I, R24P, and 33ins24), including benign nevi, showed nuclear mislocalization, confirming previous studies suggesting that subcellular distribution indicates functional impairment of p16.