Investigation of prognostic significance of CD109 expression in women with vulvar squamous cell carcinoma

The application of Aptamer in biomarker discovery

Biomarkers are detectable molecules that can reflect specific physiological states of cells, organs, and organisms and therefore be regarded as indicators for specific diseases. And the discovery of biomarkers plays an essential role in cancer management from the initial diagnosis to the final treatment regime. Practically, reliable clinical biomarkers are still limited, restricted by the suboptimal methods in biomarker discovery. Nucleic acid aptamers nowadays could be used as a powerful tool in the discovery of protein biomarkers. Nucleic acid aptamers are single-strand oligonucleotides that can specifically bind to various targets with high affinity. As artificial ssDNA or RNA, aptamers possess unique advantages compared to conventional antibodies. They can be flexible in design, low immunogenicity, relative chemical/thermos stability, as well as modifying convenience. Several SELEX (Systematic Evolution of Ligands by Exponential Enrichment) based methods have been generated recently to construct aptamers for discovering new biomarkers in different cell locations. Secretome SELEX-based aptamers selection can facilitate the identification of secreted protein biomarkers. The aptamers developed by cell-SELEX can be used to unveil those biomarkers presented on the cell surface. The aptamers from tissue-SELEX could target intracellular biomarkers. And as a multiplexed protein biomarker detection technology, aptamer-based SOMAScan can analyze thousands of proteins in a single run. In this review, we will introduce the principle and workflow of variations of SELEX-based methods, including secretome SELEX, ADAPT, Cell-SELEX and tissue SELEX. Another powerful proteome analyzing tool, SOMAScan, will also be covered. In the second half of this review, how these methods accelerate biomarker discovery in various diseases, including cardiovascular diseases, cancer and neurodegenerative diseases, will be discussed.

Prognostic Significance of CD109 Expression in Patients with Ovarian Epithelial Cancer

Background

Ovarian epithelial cancer (OEC) is the second-most common gynecologic malignancy. CD109 expression is elevated in human tumor cell lines and carcinomas. A previous study showed that CD109 expression is elevated in human tumor cell lines and CD109 plays a role in cancer progression. Therefore, this study aimed to determine whether CD109 is expressed in OEC and can be useful in predicting the prognosis.

Methods

Immunohistochemical staining for CD109 and reverse transcription-quantitative polymerase chain reaction was performed. Then we compared CD109 expression and chemoresistance, overall survival, and recurrence-free survival of OEC patients. Chemoresistance was evaluated by dividing into good-response group and poor-response group by the time to recurrence after chemotherapy.

Results

CD109 expression was associated with overall survival (p = .020), but not recurrence-free survival (p = .290). CD109 expression was not an independent risk factor for overall survival due to its reliability (hazard ratio, 1.58; p = .160; 95% confidence interval, 0.82 to 3.05), although we found that CD109 positivity was related to chemoresistance. The poor-response group showed higher rates of CD109 expression than the good-response group (93.8% vs 66.7%, p = .047). Also, the CD109 mRNA expression level was 2.88 times higher in the poor-response group as compared to the good-response group (p = .001).

Conclusions

Examining the CD109 expression in patients with OEC may be helpful in predicting survival and chemotherapeutic effect.

Development of novel monoclonal antibodies against CD109 overexpressed in human pancreatic cancer

Pancreatic cancer is one of the most aggressive and lethal types of cancer, and more effective therapeutic agents are urgently needed. Overexpressed cell surface antigens are ideal targets for therapy with monoclonal antibody (mAb)-based drugs, but none have been approved for the treatment of pancreatic cancer. Here, we report development of two novel mouse mAbs, KU42.33C and KU43.13A, against the human pancreatic cancer cell line BxPC-3. Using ELISA, flow cytometry, competitive assay and immunoprecipitation followed by mass spectrometry, we discovered that these two mAbs target two distinct epitopes on the external domain of CD109 that are overexpressed by varying amounts in human pancreatic cancer cell lines. Treatment with these two naked antibodies alone did not affect tumour cell growth or migration in vitro. Of the two mAbs, only KU42.33C was useful in determining the expression of CD109 in tumour cells by Western blot and immunohistochemistry. Interestingly, immunohistochemistry of human pancreatic carcinoma tissue arrays with mAb KU42.33C showed that 94% of the 65 human pancreatic adenocarcinoma cases were CD109 positive, with no expression in normal pancreatic tissues. Our results suggest that these two novel mAbs are excellent tools for determining the expression level of CD109 in the tumour specimens and sera of patients with a wide range of cancers, in particular pancreatic cancer, and for investigating its diagnostic, prognostic and predictive value. Further research is warranted and should aim to unravel the therapeutic potential of the humanised forms or conjugated versions of such antibodies in patients whose tumours overexpress CD109 antigen.

Association of down-regulation of CD109 expression with up-expression of Smad7 in pathogenesis of psoriasis

Transforming growth factor (TGF)-β signaling plays an important role in the pathogenesis of psoriasis. CD109, a novel TGF-β co-receptor, which inhibits TGF-β signaling by enhancing Smad7-dependent degradation of TGF-β type I receptor (TGF-β RI), is abnormally expressed in psoriasis. To date, the expression of Smad7 and the correlation between CD109 and Smad7 expression in psoriasis have not been fully elucidated. This study was designed to investigate the expression and the correlation of CD109 and TGF-β signaling associated proteins in psoriasis and their roles in the pathogenesis of psoriasis. Thirty-two psoriasis specimens were subjected to immunohistochemical staining for CD109, Smad7, TGF-β RI and Ki67. Ten normal skin (NS) specimens served as controls. The positive expression rate (% positive cells) of Smad7 and Ki67 in psoriasis was significantly higher than in NS (62.6%±19.9% vs. 17.2%±4.4%, and 50.7%±14.3% vs. 19.5%±3.2%, respectively, P<0.001), and the expression levels of CD109 and TGF-β RI were reduced significantly in psoriasis as compared with NS (8.1%±6.7% vs. 35.8%±6.7% and 27.3%±3.4% vs. 3.0%±3.4%, respectively, P<0.001). There were significantly negative correlations between CD109 and Smad7 (r=-0.831, P<0.01). These findings indicated that CD109 might play a certain role in the pathogenesis of psoriasis. Lower expression of CD109 and TGF-β RI was highly correlated with higher expression of Smad7 and Ki67, suggesting that CD109 may induce the pathogenesis of psoriasis through Smad7-mediated degradation of TGF-β RI, and lead to the termination of TGF-β signaling.

CD109 is a potential target for triple-negative breast cancer

The aim of this study is to explore the expression of CD109 in breast cancer stem cells and the relationship between CD109 protein and clinicopathological characteristics of breast cancer. CD44+/CD24- tumor cells (CSCs) were selected by flow cytometry. The protein expression of CD109 was analyzed by immunohistochemistry staining, and the relationship between CD109 and clinicopathological parameters of breast cancer was determined. CD109 positively regulated the proliferation of breast CSCs in vitro, and CD109 protein expression was significantly higher in triple-negative breast cancer (TNBC) compared to non-TNBC (63.78 vs. 3.71 %, P = 0.001). Moreover, CD109 protein expression was related to the histological grade of breast cancer (P = 0.015), whereas age (P = 0.731), tumor size (P = 0.995), clinical stage (P = 0.644), and lymph node metastasis (P = 0.924) were not. In the logistic regression model, histological grade (P = 0.001) and molecular type (P = 0.001) were significantly related to CD109 expression. The patients with high expression of CD109 protein had significantly poorer postoperative disease-specific survival than those with no or low expression of CD109 protein (P = 0.001). In the Cox regression, CD109 was an independent prognostic factor (P = 0.001). CD109 is highly expressed in TNBC and is a potential biomarker for the initiation, progression, and differentiation of breast cancer tumors.