Stefania Damiani

Frequent and Focal FGFR1 Amplification Associates with Therapeutically Tractable FGFR1 Dependency in Squamous Cell Lung Cancer

FGFR1 amplification provides a therapeutic target for squamous cell lung cancer, which is resistant to other targeted lung cancer drugs. A Smoking Gun for Lung Cancer Detectives and scientists alike need strong evidence to take their cases to the judge, who for scientists is often a patient with a deadly disease. Yet, new culprits are sometimes found that can break a case wide open. Lung cancer, which accounts for more than 10% of the global cancer burden, has a poor prognosis and inadequately responds to chemotherapy and radiotherapy. New targeted treatments for lung adenocarcinomas inhibit the oncogenic versions of signaling protein kinases that arise from mutations typically found in lung cancer patients who have never smoked. However, smokers frequently suffer from a different deviant, squamous cell lung cancers, for which there are no known molecular genetic targets for therapy. Now, Weiss et al. have fingered a new suspect in smoking-related lung cancer: amplification of the FGFR1 gene, which encodes the fibroblast growth factor receptor 1 tyrosine kinase (FGFR1). To identify therapeutically viable genetic alterations that may influence squamous cell lung cancer, Weiss et al. performed genomic profiles on a large set of lung cancer specimens. Squamous cell lung cancer samples showed FGFR1 amplification, which was not found in other lung cancer subtypes. The authors then determined that a molecule that broadly inhibits FGF receptor function could block tumor growth and cause cell death in the cancers that expressed high amounts of the FGFR1 gene product in a manner that was dependent on FGFR1 expression. Moreover, FGFR1 inhibition resulted in a considerable decrease in tumor size in a mouse model of FGFR1-amplified lung cancer. This culmination of evidence implies that inhibition of this receptor tyrosine kinase should be explored as a candidate therapy for corralling squamous cell lung cancer in smokers. Lung cancer remains one of the leading causes of cancer-related death in developed countries. Although lung adenocarcinomas with EGFR mutations or EML4-ALK fusions respond to treatment by epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) inhibition, respectively, squamous cell lung cancer currently lacks therapeutically exploitable genetic alterations. We conducted a systematic search in a set of 232 lung cancer specimens for genetic alterations that were therapeutically amenable and then performed high-resolution gene copy number analyses. We identified frequent and focal fibroblast growth factor receptor 1 (FGFR1) amplification in squamous cell lung cancer (n = 155), but not in other lung cancer subtypes, and, by fluorescence in situ hybridization, confirmed the presence of FGFR1 amplifications in an independent cohort of squamous cell lung cancer samples (22% of cases). Using cell-based screening with the FGFR inhibitor PD173074 in a large (n = 83) panel of lung cancer cell lines, we demonstrated that this compound inhibited growth and induced apoptosis specifically in those lung cancer cells carrying amplified FGFR1. We validated the FGFR1 dependence of FGFR1-amplified cell lines by FGFR1 knockdown and by ectopic expression of an FGFR1-resistant allele (FGFR1V561M), which rescued FGFR1-amplified cells from PD173074-mediated cytotoxicity. Finally, we showed that inhibition of FGFR1 with a small molecule led to significant tumor shrinkage in vivo. Thus, focal FGFR1 amplification is common in squamous cell lung cancer and associated with tumor growth and survival, suggesting that FGFR inhibitors may be a viable therapeutic option in this cohort of patients.

Integrative genome analyses identify key somatic driver mutations of small-cell lung cancer

Small-cell lung cancer (SCLC) is an aggressive lung tumor subtype with poor prognosis. We sequenced 29 SCLC exomes, 2 genomes and 15 transcriptomes and found an extremely high mutation rate of 7.4 ± 1 protein-changing mutations per million base pairs. Therefore, we conducted integrated analyses of the various data sets to identify pathogenetically relevant mutated genes. In all cases, we found evidence for inactivation of TP53 and RB1 and identified recurrent mutations in the CREBBP, EP300 and MLL genes that encode histone modifiers. Furthermore, we observed mutations in PTEN, SLIT2 and EPHA7, as well as focal amplifications of the FGFR1 tyrosine kinase gene. Finally, we detected many of the alterations found in humans in SCLC tumors from Tp53 and Rb1 double knockout mice. Our study implicates histone modification as a major feature of SCLC, reveals potentially therapeutically tractable genomic alterations and provides a generalizable framework for the identification of biologically relevant genes in the context of high mutational background.

Antigen retrieval techniques in immunohistochemistry: comparison of different methods.

Routine sections of normal and pathological samples fixed in 10 per cent buffered formalin or B5, including EDTA‐decalcified bone‐marrow biopsies, were tested with 61 antibodies following heating in three different fluids: 0·01 m citrate buffer (pH 6·0), 0·1 m Tris–HCl (pH 8·0), and 1 mm EDTA–NaOH solution (pH 8·0). The sections underwent either three cycles of microwave treatment (5 min each) or pressure cooking for 1–2 min. The alkaline phosphatase/anti‐alkaline phosphatase (APAAP) technique was used as the standard detection method; with 16 antibodies a slightly modified streptavidin–biotin complex (SABC)‐immunoperoxidase technique was applied in parallel. The results obtained were compared with those observed without any antigen retrieval (AR), or following section digestion with 0·05 per cent protease XIV at 37°C for 5 min. Chess‐board titration tests showed that all antibodies but one profited by AR. Protease XIV digestion represented the gold standard for five antibodies, while 55 produced optimal results following the application of heat‐based AR. By comparison with the other fluids, EDTA appeared to be superior in terms of both staining intensity and the number of marked cells. These results were independent of tissue processing, immunohistochemical approach, and heating device. Pressure cooking was found to be more convenient on practical grounds, as it allowed the simultaneous handling of a large number of slides and a time saving of 1 min 30 s, representing the proper time for the treatment.

Molecular Cytogenetic Comparison of Apocrine Hyperplasia and Apocrine Carcinoma of the Breast

The relationship of apocrine metaplasia to invasive breast cancer is controversial. Different authors have reported that apocrine differentiation in proliferative lesions may be a risk factor, a precursor lesion, or have no association with malignancy. The aim of this study was to compare the genetic alterations in benign apocrine hyperplasia with apocrine ductal carcinoma in situ (DCIS) and invasive apocrine carcinomas of the breast using comparative genomic hybridization. The mean number of alterations in apocrine hyperplasia was 4.1 (n = 10) compared to 10.2 in apocrine DCIS (n = 10) and 14.8 (n = 4) in invasive carcinoma. The most common alterations in apocrine hyperplasia were gains of 2q, 13q, and 1p and losses of 1p, 17q, 22q, 2p, 10q, and 16q. Apocrine DCIS and invasive carcinomas showed gains of 1q, 2q, 1p, and losses of 1p, 22q, 17q, 12q, and 16q as their most common DNA copy number changes. Apocrine hyperplasia is considered to be a benign lesion and its relationship to invasive carcinoma remains unclear. Our data suggest that some apocrine hyperplasias may be clonal proliferations. The mean number of alterations are lower in apocrine hyperplasia, however the changes show considerable overlap with those identified in in situ and invasive apocrine carcinoma. These alterations are also commonly seen in nonapocrine breast cancer. The data are consistent with apocrine hyperplasia as a putative nonobligate precursor of apocrine carcinoma.

Solitary fibrous tumour (myofibroblastoma) of the breast.

Three new cases of the spindle cell tumour of the breast, usually termed myofibroblastoma, are reported. The histology and the immunological profile (expression of vimentin, CD34 antigen and of muscular markers) appear similar to those of solitary fibrous tumours recently described in various sites. It is proposed to include these mammary lesions into the group of solitary fibrous tumours and to regard breast as an additional site of origin.

Small cell neuroendocrine carcinoma with skeletal muscle differentiation: report of three cases.

Three cases of neuroendocrine carcinoma showing skeletal muscle differentiation are presented. The tumors were located in the skin and subcutaneous tissue, the urinary bladder, and the nasal cavity respectively, and were composed by two cell types admixed intimately with each other. One cell type had features identical to those seen in conventional small cell neuroendocrine carcinoma, including scanty cytoplasm, round nuclei with fine granular chromatin, immunohistochemical reactivity for neuron-specific enolase, chromogranin and cytokeratins, and electron-dense granules on ultrastructural examination. The second cell type was either plasmacytoid or elongated and straplike, with abundant eosinophilic cytoplasm and irregular nuclei with prominent nucleoli. These cells showed immunohistochemical positivity for desmin, sarcomeric actin, myoglobin, and myogenin. They also exhibited ultrastructural evidence of rhabdomyoblastic differentiation in the form of contractile filaments with abortive Z-band formation. An origin from a cell capable of dual differentiation toward neuroendocrine and rhabdomyoblastic elements is postulated for these tumors.

Myoepithelial cells and basal lamina in poorly differentiated in situ duct carcinoma of the breast. An immunocytochemical study.

Abstract A retrospective study was made of 38 selected brest tumours with a poorly differentiated in situ duct component. These were classified on haematoxylin and eosin (H&E) as ductal carcinoma in situ (DCIS; 10 cases), DCIS with invasion (17 cases) and DCIS with features suggestive of for stromal invasion (11 cases). The last were these lesions composed of neoplastic ducts with irregular outlines and a myoepithelial layer that was not clearly evident or large neoplastic ducts growing close together or surrounded by inflammatory desmoplastic stroma. Cases of DCIS involving areas of sclerosing adenosis were included in this category. Consecutive sections obtained from each case were studied with a panel of antibodies against myoepithelial cells (alpha smooth muscle actin and calponin) and basal lamina (BL) components (laminin and type IV collagen). It was found that in situ lesions showed well-formed basal lamina and/or an evident myoepithelial layer. These features were lacking in the invasive areas. Nine of the 11 cases with suggestive features of stromal invasion were reclassified as invasive duct carcinoma (5 cases)and DCIS (4 cases), according to the absence or presence of a continuous myoepithelial layer and/or basal lamina. In 2 such cases immunohistochemistry yielded equivocal results and the label ”suggestive of invasion” was therefore pertinent. Immunohistochemistry facilitates the diagnosis of breast DCIS; myoepithelial and basal lamina markers are useful in differentiating microinvasive from in situ ductal carcinomas of the breast.

Neurotensin Receptor 1 Determines the Outcome of Non–Small Cell Lung Cancer

Purpose: This study aimed to investigate the role of the neurotensin/neurotensin receptor I (NTSR1) complex in non–small cell lung cancer (NSCLC) progression. Experimental Design: The expression of neurotensin and NTSR1 was studied by transcriptome analysis and immunohistochemistry in two series of 74 and 139 consecutive patients with pathologic stage I NSCLC adenocarcinoma. The findings were correlated with clinic-pathologic features. Experimental tumors were generated from the malignant human lung carcinoma cell line A459, and a subclone of LNM35, LNM-R. The role of the neurotensin signaling system on tumor growth and metastasis was investigated by small hairpin RNA–mediated silencing of NTSR1 and neurotensin. Results: Transcriptome analysis carried out in a series of 74 patients showed that the positive regulation of NTSR1 put it within the top 50 genes related with relapse-free survival. Immunohistochemistry revealed neurotensin- and NTSR1-positive staining in 60.4% and 59.7% of lung adenocarcinomas, respectively. At univariate analysis, NTSR1 expression was strongly associated with worse 5-year overall survival rate (P = 0.0081) and relapse-free survival (P = 0.0024). Multivariate analysis showed that patients over 65 years of age (P = 0.0018) and NTSR1 expression (P = 0.0034) were independent negative prognostic factors. Experimental tumor xenografts generated by neurotensin- and NTSR1-silenced human lung cancer cells revealed that neurotensin enhanced primary tumor growth and production of massive nodal metastasis via autocrine and paracrine regulation loops. Conclusion: NTSR1 expression was identified as a potential new prognostic biomarker for surgically resected stage I lung adenocarcinomas, as NTSR1 activation was shown to participate in lung cancer progression. Clin Cancer Res; 16(17); 4401–10. ©2010 AACR.

Breast tumor resembling the tall cell variant of papillary thyroid carcinoma: Report of 5 cases

Five cases of a hitherto undescribed breast tumor having histologic features similar to those of the tall cell variant papillary thyroid carcinoma are described. They were composed of columnar mitochondrion-rich to oxyphilic cells arranged in nests, papillae, and follicle-like structures. In addition, the neoplastic cells showed numerous nuclear grooves and, in two cases, nuclear pseudo-inclusions. None of the patients had previous concomitant or subsequent evidence of a thyroid tumor. Immunohistochemistry further excluded a metastasis from the thyroid in the four cases tested, as they were consistently thyroglobulin and thyroid transcription factor 1 negative.

Acinic cell carcinoma of the breast: an immunohistochemical and ultrastructural study.

Abstract The clinicopathological features of six cases of breast carcinomas showing features of acinic cell differentiation, which are similar to those seen in homologous tumors of salivary glands, are presented. The patients, all women, were 35–80 years of age. One case recurred after 4 years, and in two cases axillary lymph-node metastases were found at the time of surgery. Histologically the tumors showed a microglandular pattern merging with solid areas. Cytologically, immunohistochemically, and ultrastructurally the tumors were very similar to cases of acinic cell carcinoma of the parotid gland.The differential diagnostic criteria with microglandular adenosis and carcinomas showing granular cytoplasm are discussed. It seems that acinic cell carcinomas of the breast have to be added to the long list of tumors that affect the salivary glands and can also arise in the breast.