The risk of developing a second primary cancer is increased in patients with breast cancer, and the lung is one of the major sites involved. Moreover, the lung is the major metastatic site for breast cancers. A distinction between metastatic breast cancer and primary lung cancer can be histologically difficult, and both show an overlapping CK7 þ /CK20À immunoprofile in a majority of cases. The degree of difficulty increases with poorly differentiated tumors. We investigated differential expressions of TTF-1, Napsin A, surfactant apoprotein A, estrogen receptor, GATA-3, mammaglobin, and GCDFP-15 immunostains in 197 pulmonary carcinomas (158 adenocarcinomas, 39 squamous) and 115 invasive mammary carcinomas (91 ductal, 24 lobular type). In mammary carcinomas, estrogen receptor, GATA-3, mammaglobin, and GCDFP-15 were expressed in 74, 72, 64, and 62%, respectively, whereas TTF-1, Napsin A, and surfactant apoprotein A were all negative. The expressions were diffuse in estrogen receptor and GATA-3, and variable in mammaglobin and GCDFP-15. For a combination of estrogen receptor/mammaglobin or GATA-3/mammaglobin, 83% of mammary carcinomas were positive, and the detection rate was not improved by using all three markers. All lung squamous cell carcinomas were negative for all markers studied. TTF-1, Napsin A, and surfactant apoprotein A were positive in 80, 77, and 45% of pulmonary adenocarcinomas. None of the TTF-1-negative tumors expressed surfactant apoprotein A. GCDFP-15 was focally expressed in 2.5% of pulmonary adenocarcinomas, and estrogen receptor was focally expressed in one case (1.2%) of pulmonary adenocarcinoma. When metastasis from breast cancer is suspected in the lung, a combination of either estrogen receptor/mammaglobin or GATA-3/mammaglobin as breast markers, and a combination of TTF-1 and Napsin A as lung markers may be helpful for differentiating between the two. Caution should be taken in the interpretation of GCDFP-15 due to its occasional expression in pulmonary adenocarcinomas.

No abstract

We demonstrate the fabrication of protein·gold nanoparticle (AuNP) nanocomposites in situ, leading to distinct assemblies dependent upon protein secondary structure. In the presence of pentameric coiled-coil proteins C and Q, which contain histidine tags and have helicities of 54 and 65%, respectively, templation of AuNP results in precipitation of the protein·AuNP composites with AuNPs 6.5 nm in diameter, creating macromolecular assemblies on the micrometer scale. In the absence of the histidine tags, the resulting Cx and Qx proteins, which exhibit lower helicities of 37 and 45%, respectively, stabilize soluble protein·AuNP composites with AuNPs 4.5 nm in diameter for several days without aggregating. By manipulating protein structure via external triggers, such as TFE, we obtain control over the macromolecular conformation and overall physicochemical properties. These hybrid protein·AuNP assemblies can be readily deposited on electrodes, where they can serve as a tunable bionanocomposite kinetic barrier.