Integrated Fourier Transform Infrared Imaging and Proteomics for Identification of a Candidate Histochemical Biomarker in Bladder Cancer

Abstract

Histopathological differentiation between severe urocystitis with reactive urothelial atypia and carcinoma in situ (CIS) can be difficult, particularly after a treatment that deliberately induces an inflammatory reaction, such as intravesical instillation of Bacillus Calmette-Guèrin. However, precise grading in bladder cancer is critical for therapeutic decision making and thus requires reliable immunohistochemical biomarkers. Herein, an exemplary potential biomarker in bladder cancer was identified by the novel approach of Fourier transform infrared imaging for label-free tissue annotation of tissue thin sections. Identified regions of interest are collected by laser microdissection to provide homogeneous samples for liquid chromatographyetandem mass spectrometryebased proteomic analysis. This approach afforded label-free spatial classification with a high accuracy and without interobserver variability, along with the molecular resolution of the proteomic analysis. Cystitis and invasive highgrade urothelial carcinoma samples were analyzed. Three candidate biomarkers were identified and verified by immunohistochemistry in a small cohort, including low-grade urothelial carcinoma samples. The best-performing candidate AHNAK2 was further evaluated in a much larger independent verification cohort that also included CIS samples. Reactive urothelial atypia and CIS were distinguishable on the basis of the expression of this newly identified and verified immunohistochemical biomarker, with a sensitivity of 97% and a specificity of 69%. AHNAK2 can differentiate between reactive urothelial atypia in the setting of an acute or chronic cystitis and nonmuscle invasive-type CIS. (Am J Pathol 2019, 189: 619e631; https://doi.org/10. 1016/j.ajpath.2018.11.018) Bladder cancer is the second most common urogenital malignancy, with approximately 430,000 new cases diagnosed worldwide in 2012. 1,2 Approximately 70% to 75% of patients are newly diagnosed with nonmuscle invasive, mostly low-grade bladder cancer, whereas 25% to 30% of de novo diagnoses are high-grade bladder cancer at the stage of infiltration of the muscularis, with metastases observed in 10% of cases. 3e5 A significant percentage (50% to 70%) of patients diagnosed with nonmuscle invasive cancer will have multiple recurrences, and 10% to 15% will even progress to invasion. 3,6,7 A special case of bladder cancer is carcinoma in situ (CIS), which is a flat, noninvasive tumor with a rate of progression to an invasive state of approximately 54%. 8

Deimination Protein Profiles in Alligator mississippiensis Reveal Plasma and Extracellular Vesicle-Specific Signatures Relating to Immunity, Metabolic Function, and Gene Regulation

“…Furthermore, roles in cancer are implicated, and AHNAK has been shown to facilitate EV release in mammary carcinoma cells (165), therefore playing critical roles in EV communication in the tumor environment. AHNAK has been identified as a biomarker in several, including metastatic, cancers (166)(167)(168)(169) and linked to drug resistance in cancer in association with viral infection (170). AHNAK has been is also related to stress-induced secretion of FGF1-a growth factor regulating carcinogenesis, angiogenesis, and inflammation (171) and to inherited peripheral neuropathy (172).…”

Traditional Classification and Novel Subtyping Systems for Bladder Cancer

“…With the rapid development of sequencing, mass spectrometry and other techniques, studies based on genomics and transcriptome (17), epigenetics (18), proteomics (19) and other omics (20)(21)(22) will provide a new direction for the accurate diagnosis and treatment of bladder cancer. A good classification system should meet the following criteria: I.…”

PDAC-ANN: an artificial neural network to predict pancreatic ductal adenocarcinoma based on gene expression

“…The AHNAK2 function in PDAC in poorly described; however, another similar AHNAK gene is involved with migration and the epithelial-mesenchymal transition, indicating the AHNAK2 may be involved in these processes as well [67]. AHNAK2 high expression is associated with PDAC poor prognosis and is also expressed in bladder and kidney cancer [68,69].…”