Multispectral imaging reveals hyper active TGF-β signaling in colorectal cancer

Advances in multiplex immunohistochemistry (IHC) techniques and digital pathology platforms allow quantification of multiple proteins at same tissue section and produce continuous data. TGF-β signaling plays crucial and complex roles in colorectal cancer (CRC). We here aimed to investigate clinical pathological relevant of proteins involved in TGF-β signaling at CRC tissues. Multiplex fluorescent IHC was used to quantitative analysis. The levels of eight proteins (TGF-β1, TGFBRI, TGFBRII, SMAD4, SMAD2/3, p-SMAD2/3, SMAD1/5/9, and p-SMAD1/5/9) were determined in TMA sections. Quantitative analysis was carried out by a scoring system by InForm software. It revealed that TGF-β signaling was hyper active. The levels of TGF-β1, TGFBRI, TGFBRII, SMAD4, SMAD1/5/9 and p-SMAD2/3 were significantly increased in cancer tissues when compared their levels in normal tissues. Furthermore, the levels of eight proteins in stroma were significantly lower than the levels that in cancer tissues. Clinical pathological relevant analysis exhibited that TGF-β signaling inclined to suppress the progression of tumor. SMAD1/5/9, TGFBRII, SMAD2/3 were confirmed as significant predictors for overall survival. In conclusion, we established a method based on multispectral imaging to extensively explore the clinical relevant of TGF-β signaling proteins. These results provided an opportunity to consider the novel application for proteins involving TGF-β signaling that used as diagnostic or prognostic biomarkers to conduct tumor therapy.