Fibroblast Activation Protein-α (FAP) Identifies Stromal Invasion in Colorectal Neoplasia

Fibroblast Activation Protein Alpha (FAPα) as a Promising Target in the Diagnostics and Treatment of Cancer and Fibrotic Diseases: Recent Approaches to Imaging and Assessment of Functional Activity

Fibroblast activation protein alpha (FAPα) is a transmembrane serine peptidase and a well-known marker of activated fibroblasts that are formed during onco- and fibrogenesis and play an important role in the progression of cancer and fibrosis. Identification of FAPα-positive cells is widely used to visualize pathological changes in the stroma in the diagnosis and treatment of cancer diseases. Recent evidence suggests that FAPα itself contributes to the development of tumors and fibrosis-associated diseases through its enzymatic activity and other mechanisms. Various methods for visualization and evaluation of FAPα enzymatic activity are being developed, which are essential for deciphering the role of FAPα in the development of stromal pathologies. Here we discuss current approaches to visualization and regulation of FAPα enzymatic activity.

FAP-α is an effective tool to evaluate stroma invasion of lung adenocarcinoma

The main difficulty in the diagnosis of atypical in situ adenocarcinoma lies in the distinction between true and false stromal invasion. Moreover, how to identify local alveolar wall collapse in situ lung adenocarcinoma and how to identify whether the trapped adenoid structure around scar is an invasion component have become the key points for accurate diagnosis of lung adenocarcinoma. In the present study, we detected 40 cases of lung adenocarcinoma in situ and 40 cases of invasive adenocarcinoma by using immunohistochemical techniques. We found FAP-α had not immunreactivity in the stroma of adenocarcinoma in situ. However, it stained in the stroma of invasive areas in lung adenocarcinoma. FAP-α staining pattern could represent hyperplastic myofibroblast and demonstrated the true invasion of stroma. This study provides strong evidence that FAP-α is an effective tool to evaluate the presence or absence of stroma invasion of lung adenocarcinoma. Our findings will contribute to the accurate diagnosis of lung invasive adenocarcinoma.

Clear Cell Renal Cell Carcinoma: A Test Bench for Investigating Tumor Complexity

Clear cell renal cell carcinoma (CCRCC), by far the most common renal cancer subtype, is an aggressive tumor variant, serving in recent years as a prolific test bench in cancer research [...].