Cathepsin B expression in colorectal cancer in a Middle East population: Potential value as a tumor biomarker for late disease stages

Abstract

Cathepsin B (CTSB), is a cysteine protease belonging to the cathepsin (Clan CA) family. The diagnostic and prognostic significance of increased CTSB in the serum of cancer patients have been evaluated for some tumor types. CTSB serum and protein levels have also been reported previously in colorectal cancer (CRC) with contradictory results. The aim of the present study was to investigate CTSB expression in CRC patients and the association of CTSB expression with various tumor stages in a Middle East population. Serum CTSB levels were evaluated in 70 patients and 20 healthy control subjects using enzyme-linked immunosorbant assay (ELISA) technique. CTSB expression was determined in 100 pairs of CRC tumor and adjacent normal colonic tissue using quantitative PCR for mRNA levels. Detection of CTSB protein expression in tissues was carried out using both immunohistochemistry and western blotting techniques. ELISA analysis showed that in sera obtained from CRC patients, the CTSB concentration was significantly higher in late stage patients with lymph node metastases when compared to early stage patients with values of 2.9 and 0.33 ng/ml, respectively (P=0.001). The majority of tumors studied had detectable CTSB protein expression with significant increased positive staining in tumors cells when compared with matched normal colon subjects (P=0.006). The mRNA expression in early stage CRC compared to late stage CRC was 0.04±0.01 and 0.07±0.02, respectively. Increased mRNA expression was more frequently observed in the advanced cancer stages with lymph node metastases when compared with the control (P=0.002). Mann-Whitney test and paired t-test were used to compare serum CTSB and mRNA levels in early and late tumor stage. A subset of four paired tissue extracts were analyzed by western blotting. The result confirmed a consistent increase in the CTSB protein expression level in tumor tissues compared with that noted in the adjacent normal mucosal cells. These findings indicate that CTSB may be an important prognostic biomarker for late stage CRC and cases with lymph node metastases in the Middle Eastern population. Monitoring serum CTSB in CRC patients may predict and/or diagnose cases with lymph node metastases.

20‐Hydroxyecdysone‐upregulated proteases involved in Bombyx larval fat body destruction

“…Orthologues of cathepsin B from Callosobruchus maculatus and human can both be detected with two bands by western blotting (Ahn et al ., ; Abdulla et al ., ). As expected here, the pro‐BmCatB could be detected at 4M and the period from later fifth instar to wandering, while mature BmCatB existed over the whole developmental stages, with high abundance at the 4M and prepupal stages (Fig.…”

“…Orthologues of cathepsin B from Callosobruchus maculatus and human can both be detected with two bands by western blotting (Ahn et al, 2007;Abdulla et al, 2017).…”

IL-17 and colorectal cancer risk in the Middle East: gene polymorphisms and expression

“…Immunohistochemical staining was conducted on 5 µm sections of tissue microarray (TMA) blocks as previously described. 23 IL17A staining was performed using a streptavidin-biotinylated horseradish peroxidase (S-ABC) kit (Novo Link Max Polymer Detection System; Novocastra) involving quenching of endogenous peroxidase activity with 3% hydrogen peroxide, blocking of nonspecific binding of antibodies (Novocastra) prior to incubation first with human IL-17 (H-132) polyclonal rabbit antibody (sc-7927) (Santa Cruz Biotechnology, Inc., Dallas, TX, USA) at a dilution of 1:100 and then with biotinylated anti-rabbit immunogloublin G (Novocastra). Peroxidase was detected using diaminobenzedine substrate (Novocastra), and slides were counterstained with Mayer’s hematoxylin (Novocastra).…”

“…High-resolution, whole-slide digital scans of all TMA glass slides were created using a ScanScope slide scanner (Aperio Technologies, Inc.) as previously described. 23 …”

Circumventing AKT-Associated Radioresistance in Oral Cancer by Novel Nanoparticle-Encapsulated Capivasertib

“…Tumor-seeking NPs can be achieved by modulating the tumor microenvironment to disrupt some barriers for NP delivery [16]. CTSB belongs to a family of lysosomal cysteine proteases, whose expression levels are significantly increased in serum of patients with colorectal cancer compared with matched normal colon subjects [29], suggesting that CTSB may represent a potential target for NP-based drugs in the treatment of colorectal cancer. Interestingly, profound CTSB upregulation was also found in head and neck cancer tissues compared with paired adjacent normal tissues [30].…”