Identification of cytokines and their cellular origins
IL6 is known to contribute to the development and/or progression of prostate cancer, yet the source of IL6 production has not been well defined. Yu et al. used RNAscope ISH to show that IL6 expression was nearly exclusively restricted to the prostate stromal compartment. IL6 was detected in the endothelium, stroma, and areas of inflammation, but it was not detected in primary and metastatic prostate adenocarcinoma cells. These findings suggest that paracrine, and not autocrine, IL6 production is associated with prostate cancer disease progression. A paracrine role for IL6 in prostate cancer patients: Lack of production by primary or metastatic tumor cells

Detection of long non-coding RNA (lncRNA) in inflammatory diseases
Long non-coding RNAs (lncRNAs) are emerging as unique inflammatory biomarkers that may be associated with a physiological or diseased state. Castellanos-Rubio et al. have identified a lncRNA, lnc13, that is associated with susceptibility to celiac disease. Because lncRNAs do not translate into protein, RNAscope ISH was used to show localization of lnc13 to the intestinal lamina propria and that lnc13 expression is decreased in patients with celiac disease. A long noncoding RNA associated with susceptibility to celiac disease.

Role of inflammatory pathways during carcinogenesis
Inflammation plays a critical role in the pathogenesis of ovarian cancer, and elevated systemic levels of inflammatory biomarkers are predictive of ovarian cancer progression. Gupta et al. sought out to see if differences in the cytokine TNFα by histological subtype and inflammatory exposures could provide further insight into ovarian cancer risk and pathogenesis. Due to the lack validated anti-cytokine antibodies for FFPE tissues, the authors used RNAscope ISH to show that TNFα varies by ovarian cancer histological subtype and supports a role for inflammation in ovarian carcinogenesis. TNF-α expression, risk factors, and inflammatory exposures in ovarian cancer: evidence for an inflammatory pathway of ovarian carcinogenesis?

Therapeutic potential of secreted proteins in inflammatory diseases
FNDC4 is a secreted protein that is robustly upregulated during inflammation, and could be a potential therapeutic for the treatment of inflammatory bowel disease and other inflammatory disease. To identify the cells producing Fndc4 in a mouse model of induced colitis, Bosma et al. used RNAscope ISH to show that colonic epithelial cells and a subset of immune cells in lymphoid aggregates produce Fndc4. FNDC4 acts as an anti-inflammatory factor on macrophages and improves colitis in mice.

Dual ISH-IHC to detect cytokines during inflammatory responses
Innate lymphoid cells (ILCs) are tissue-resident innate immune lymphocytes with diverse roles in mucosal inflammation. Silver et al. found that group 2 ILC (ILC2) cells exhibit functional plasticity depending on the inflammatory milieu. Dual RNAscope ISH-IHC detected inflammatory signals that co-localized with ILCs in lung tissue from mice infected with influenza A virus: ISH detected the secreted cytokines IL18 and IL12 while IHC detected GFP, which represented ST2 (IL33 receptor) expression. These data revealed that myeloid-derived cells expressing IL12 and IL18 mRNA were frequently identified in close proximity to ILCs expressing the IL33 receptor within inflamed airways. Inflammatory triggers associated with exacerbations of COPD orchestrate plasticity of group 2 innate lymphoid cells in the lungs