Proteomic technologies like microarray analysis are key players in the molecular profiling of cancer and the discovery of novel genes and proteins involved carcinogenesis, tumor initiation and progression. In particular, tissue arrays are vital tools, which enable researchers to analyze protein expression profiles and biomarkers on tumor specimens to determine their potential clinical significance and role in oncogenesis. Our laboratory wanted to examine the differential expression of signaling proteins in normal and neoplastic lung tissues, therefore we chose to buy the ISU ABXIS lung cancer tissue microarray for our studies. More specifically, we wanted to assess the relative expression of survivin in lung cancer tissues versus normal lung tissues. The tissue arrays were probed with anti- survivin monoclonal antibody (suitable for immnohistochemistry) overnight at 4ºC. Subsequently, the arrays were incubated with secondary antibody conujated to horseradish peroxidase at room temperature. Color was developed using the DAB (diaminobenzidine) reagent and analyzed by phase contrast microscopy.
The ISU ABXIS lung cancer tissue microarray consists of an array of paraffin-embedded neoplastic and normal tissue. This tissue array includes 80 closely spaced tissue samples of a wide variety of lung tumors including adenocarcinomas, pleural effusion squamous cell carcinomas, bronchioalveolar carcinomas, large cell carcinomas and small cell lung cancer tissues. In addition to these tumor samples, the array includes matched normal lung tissues corresponding to each of these lung cancers. Apart from lung carcinoma, ISU ABXIS also sells tissue arrays involving a variety of human cancers like liver cancer, pancreatic cancer and breast cancer. The ISU ABXIS tissue array is an excellent tool to analyze protein expression profiles in cancers. The use of these arrays is manifold, including histochemical staining and immunohistochemical/immunofluorescent staining. The tissue array can be stored dessicated at 4ºC indefinitely. Both H&E (Hemotoxylin and Eosin) staining as well as immunohistochemical staining on the tumor specimens of the array is highly reproducible. Each tumor sample is provided in duplicate to ensure consistent results. For example the lung cancer tissue array we obtained from ISU ABXIS had 15 lung adenocarcinoma tissue samples, 15 lung squamous cell carcinoma, 3 bronchoalveolar lung carcinoma, 5 large cell lung cancers, 2 small cells lung cancers, each of them in duplicate. Additionally, the array contained a single sample of normal tissue matched to each of these types of lung cancers. The technical manual accompanying the arrays contains detailed pathological and clinical information about the normal as well as cancer tissues. The price of these arrays is extremely reasonable so they are affordable for any laboratory. In combination with other DNA/gene profiling methods and high-throughput screening assays, the ISU ABXIS tissue arrays can provide novel tools for cancer diagnosis and management.
I cannot think of a disadvantage of using ISU ABXIS tissue arrays. The arrays are optimally priced and the data obtained from these arrays is of high quality and extremely reproducible. The technical assistance from the company is excellent. The signals obtained from the tissue array can be reproducibly quantified using a microscope equipped with a slide scanner. It would be great if ISU ABXIS also provided arrays involving tumor samples from a single type of lung carcinomas, say bronchioalveolar carcinoma, along with the pathologic matched normal tissues. In conclusion, I would recommend them as an indispensable research tool for all laboratories involved in molecular profiling of lung cancer.
Piyali Dasgupta
Postdoctoral Fellow
H. Lee Moffitt Cancer Center
Drug Discovery